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Photoelectric sensor enables synchronization of the rotating mirror in a high-speed framing camera with the passage of a very-high-velocity droplet to obtain direct photographic data on droplet breakup. It detects droplet movement across a high intensity light beam and generates a signal triggering the camera.
Fast-framing cameras record data obtained by a multichannel hodoscope which monitors reactor physics experiments. The cameras provide high rates of data acquisition at low equipment cost.
Low light level slow scan Owl TV camera system with secondary electron conduction camera tube for satellite-borne observation of auroral light emission
Camera is modified by inserting optical imaging system between lens and film. This system requires no electrical power, is low in weight, and adds nothing to external size of the camera.
Results are presented of engineering tests of the Surveyor III television camera, which resided on the moon for 2 and 1/2 years before being brought back to earth by the Apollo XII astronauts. Electric circuits, electrical, mechanical, and optical components and subsystems, the vidicon tube, and a variety of internal materials and surface coatings were examined to determine the effects of lunar exposure. Anomalies and failures uncovered were analyzed. For the most part, the camera parts withstood the extreme environment exceedingly well except where degradation of obsolete parts or suspect components had been anticipated. No significant evidence of cold welding was observed, and the anomalies were largely attributable to causes other than lunar exposure. Very little evidence of micrometeoroid impact was noted. Discoloration of material surfaces -- one of the major effects noted--was found to be due to lunar dust contamination and radiation damage. The extensive test data contained in this report are supplemented by results of tests of other Surveyor parts retrieved by the Apollo XII astronauts, which are contained in a companion report.
The results of astrometric and photogrammetric plate reduction techniques for a short focal length camera are compared. Several astrometric models are tested on entire and limited plate areas to analyze their ability to remove systematic errors from interpolated satellite directions using a rigorous photogrammetric reduction as a standard. Residual plots are employed to graphically illustrate the analysis. Conclusions are made as to what conditions will permit the astrometric reduction to achieve comparable accuracies to those of photogrammetric reduction when applied for short focal length ballistic cameras.
A new mathematical model is presented which describes the image produced by a focal plane shutter-equipped camera. The model is based upon the well-known collinearity condition equations and incorporates both the translational and rotational motion of the camera during the exposure interval. The first differentials of the model with respect to exposure interval, delta t, yield the general matrix expressions for image velocities which may be simplified to known cases. The exposure interval, delta t, may be replaced under certain circumstances with a function incorporating blind velocity and image position if desired. The model is tested using simulated Lunar Orbiter data and found to be computationally stable as well as providing excellent results, provided that some external information is available on the velocity parameters.
Focus control performs function of automatically focusing facsimile camera throughout object field being scanned. It does this by determining and adjusting focus of imaging sensor accordingly. Since facsimile camera images a scene by scanning discrete strips, it is possible to have entire three-dimensional scene in perfect focus at point of imaging by use of focus control.
Definition is made of all television camera locations as well as the specific area to be covered by each camera to provide the television coverage of Skylab testing and launches in accordance with operational and engineering requirements.
It was demonstrated that the multispectral image dissector camera is able to provide composite pictures of the earth surface from high altitude overflights. An electronic deflection feature was used to inject the gyro error signal into the camera for correction of aircraft motion.
The direct-coupled (DC) mode of detector operation is evaluated for use in a facsimile camera. Photodiode-preamplifier sensitivity is described in terms of photodiode responsivity and possible noise sources resulting from the photodiode and preamplifier. Responsivity and noise limitations are experimentally verified and used to predict photodiode-preamplifier sensitivity under a wide range of operating conditions. Results demonstrate that the DC mode offers advantages in sensitivity and reduced mechanical complexity for facsimile cameras over the more common technique of chopping the radiation and ac amplifying the resultant signal.
An electronic viewer for real-time viewing and processing of multiband camera imagery is described. The Multiband Camera Film Viewer (MCFV) is a high-resolution, 1000-line system scanning three channels of multiband imagery. The MCFV provides a calibrated output from each of the three channels for viewing in composite true color, analog false-color, and digitized, enhanced false color.
Magnetically-focused electronographic cameras have been under development at the Naval Research Laboratory for use in far-ultraviolet imagery and spectrography, primarily in astronomical and optical-geophysical observations from sounding rockets and space vehicles. Most of this work has been with cameras incorporating internal optics of the Schmidt or wide-field all-reflecting types. More recently, we have begun development of electronographic spectrographs incorporating an internal concave grating, operating at normal or grazing incidence. We also are developing electronographic image tubes of the conventional end-window-photo-cathode type, for far-ultraviolet imagery at the focus of a large space telescope, with image formats up to 120 mm in diameter.
Review of the performance characteristics of the facsimile camera, emphasizing its line-scan sampling process; the design tradeoffs which are imposed by planetary lander missions, emphasizing those tradeoffs which define the Viking Lander Camera parameters; and new concepts which are currently being investigated for future planetary lander missions, emphasizing an integrated imagery and spectrometry concept.
The large volume of picture data produced by the Mariner 9 Television Experiment, in addition to providing a description of the planet Mars, emphasizes the need for in situ verification of camera performance. Such data provide the basis for initial quantitative image interpretation by confirmation of the relevance of preflight measurement. This information must be the result of planned calibration sequences rather than extraction from nominal mission photography. A lack of sufficient numbers of frames restricted Mariner camera verifications to only limited operational modes under optimal conditions and required significant extrapolation over the duration of the mission. The evidence does suggest that measurable photometric changes occurred, whereas agreement with preflight data is observed for other parameters.
Versatility of commercially-available camera system permits wide range of enlargement (up to 10X) and reduction (down to 1/8) to be achieved with standard lenses. Use of easily interchangeable camera backs permits photographic formats from 35 mm to 10.2 X 12.7 cm (4 x 5 in) and permits easy use of black and white and color films and Polaroid materials.
In addition to imaging the surrounding terrain, planetary lander cameras may also be used to survey the stars to aid in locating the lander site. The response of the facsimile camera, which was selected for the Viking lander missions to Mars, to a radiant point source is formulated and shown to result in a statistical rather than deterministic signal. The signal statistics are derived and magnitudes are evaluated for the brighter visual and red stars. The probability of detecting the resultant statistical signals in photosensor and preamplifier noise and the associated probability of false alarms are also determined.
A concept which utilizes interference filters and photodetector arrays to integrate spectrometry with the basic imagery function of a facsimile camera is described and analyzed. The analysis considers spectral resolution, instantaneous field of view, spectral range, and signal-to-noise ratio. Specific performance predictions for the Martian environment, the Viking facsimile camera design parameters, and a signal-to-noise ratio for each spectral band equal to or greater than 256 indicate the feasibility of obtaining a spectral resolution of 0.01 micrometers with an instantaneous field of view of about 0.1 deg in the 0.425 micrometers to 1.025 micrometers range using silicon photodetectors. A spectral resolution of 0.05 micrometers with an instantaneous field of view of about 0.6 deg in the 1.0 to 2.7 micrometers range using lead sulfide photodetectors is also feasible.