To optimize the performance of very high-resolution airborne image recording systems, many component modulation transfer functions and their interralationships must be considered. The magnitude and complexity of this task has dictated the development of a computer program. Various sets of dependent and independent variables are defined and the program utilizes their functional relationships with the total system to indicate the optimum design. A.simplified example is given to illustrate typical results and the effects of various parameters.

The U. S. Naval Airborne Pro jects Operations Group (NAPOG) has been engaged in airborne ballistic missile re-entry measurements for the Advanced Research Projects Agency (ARPA), of the Department of Defense. Airborne instrumentation used for this purpose includes long focal length telescope systems which can be mounted on an instrumented turret of an NRA-3B aircraft.

This report gives a general description of a photographic instrumentation system designed, built, and operated by Sandia Corporation for photometric observation of selected wavelengths of corona of the total solar eclipse which occurred November 12, 1966. This system was operated aboard a USAF C-135 aircraft flying with the moon's shadow to enhance the chances of optimum observation of the event and was automatically tracked to overcome the instabilities inherent in an airborne platform. The automatic tracking device was a closed-loop, hydraulically actuated servo system with an electro-optic means of error detection. The photographic part of this system consisted of nine cameras of which six operated in the visible spectrum and three operated in the ultraviolet spectrum. In addition to providing photometric data on four individual wavelengths of these two spectra, the cameras obtained polarization data on two of these wavelengths, recorded the performance of the automatic tracker, and obtained documentary event type photographs.

Mr. Murkshe ... members and guests of American Society of Photogram-metry and Society of Photo-optical Instrumentation Engineers.

The Airborne Astrographic Camera System The Airborne Astrographic Camera System (AACS) represents a unique approach to the problem of observing reentry trajectories and associated parameters from airborne observing stations. The basic principles employed by the system are the same as those with which one approaches the problem of trajectory computation using ground-based ballistic cameras. The observation of re-entry trajectories using groUnd-based cameras has become a rather well-defined and precise science, and has concurrently become a rather specialized art. Thus, it is not difficult to grasp the nature of the problems confronting investigators in the field of airborne trajectory observation who found the details of the ground-based approach rather difficult to apply to the airborne problem.

The PRESS optical aircraft program is designed to furnish optical data for coordinated re-entry physics measurements on targets observed in the vicinity of the downrange test site. To supplement this effort, a facility for calibrating the instruments used on the aircraft was established at Hickam AFB in Honolulu. The underlying philosophy of calibration is to avoid the separate calibrations of individual instrumental components, detectors and windows, relying instead on portable collimators which can be used outside the aircraft and which match the characteristics of the various instruments. In order to standardize the instrument calibrations, it is also necessary to make frequent measurements of the outputs of the portable collimators. The Hickam facility includes an optical laboratory wherein the spectral irradiance of portable collimators can be directly compared to a standard collimator whose spectral irradiance is known with reasonable accuracy. The elaborate equipment for performing these operations and the methods of operation will be de-scribed, as well as the accuracy achieved in calibration and the standards used.

The ever increasing demand for more sophisticated meteorological television satellites has inspired several organizations to investigate many unique systems and techniques. The Applied Physics Laboratory of The Johns Hopkins University, operating under contract to the Bureau of Naval Weapons, has undertaken the feasibility study of a line-scan television system for earth observation satellites. The results of this study were considered to be so successful that a limited hardware program was initiated. The television system was designed to be mounted in a gravity-gradient stabilized satellite and launched into a near-earth, sun synchronous orbit. Its lens will have a 84° x 3° field of view that will continuously sweep a wide strip of the earth's surface. The image will be transmitted from the curved focal surface of the spherically symmetrical lens to the face plate of an image dissector tube by an array of fiber optics. Linear mapping in the direction of the satellite travel, transmitted to the ground receiving stations in real time is the obvious advantage of this line-scan system. The photometry that governed the design parameters of the complete optical system are presented. The advantage of using fiber-optics rather than conventional relay lenses to transfer the image from the primary lens to the image-dissector tube are discussed. The basic mission of the television satellite is briefly defined.

The collimated output of a 70 milli-watt helium-neon laser, formed by a 3/4 inch exit pupil, and directed to a target a few thousand feet away, will be just visible against a background illuminated by the direct sun. Its intensity will be low enough for complete safety, except for extended observation directly into the collimator. The spot it forms on target can be easily photographed in exposures of one-one hundredth of a second.

Under contract AF33(657)-11053 sponsored by Aeronautical Systems Division, Air Force Systems Command, USAF, a Nortronics developed stellar-inertial navigation system operating in a C-131B aircraft tracked the Echo I sat-ellite for a total of 17 minutes in daylight and darkness. Real-time data were produced which were comparable to that from ground tracking stations.

Sky Count is an information system which utilizes high-altitude aerial photography as a comprehensive source for large scale transportation data acquisition. The main objective of the system is the development and application of airborne intelligence systems for improved operations analysis.

The development of an airborne camera system for the Aerospace Audio-Visual Service is described. It consists of a pod enclosing 16mm cameras facing fore and aft. A need for high-quality production photography, accurately framed, resulted in a closed circuit TV modification with a cockpit monitor. Later, the system suitability to high-altitude coverage of missile launches was recognized. On the Mariner III interplanetary probe, it acquired photo-data of the booster up to an altitude of 68,000 ft. AAVS pods also provided high altitude photography of Mariner IV, Centaur, and Gemini I through VII. In Vietnam, high performance aircraft are using the system to provide film for strike effectiveness as well as documentation.

The USQ-28 system was developed for the Air Force by the Kollsman Instrument Corporation to provide an improved capability for aerial photomapping and geodetic surveying. Designed to perform as a totally integrated group of equipments, the system will acquire most of the basic mapping data from the air. In a single mission, the aircraft will photographically record some 40,000 square miles of terrain and automatically process and store the auxiliary data for each exposure. The improved navigation and track-keeping accuracies of the system is provided by an inertial navigator which receives periodic updating information from precise electronic ranging or visual checkpoint fixes to known positions on the ground. This capability results in greater data reliability affording a higher rate of success per mission flown. To date, four RC-135 jets have been equipped with Q-28 systems and now represent the most advanced fleet of high-altitude, long-range photomapping air-craft capable of operational missions on a worldwide basis.

It has been recognized that a large orbiting astronomical telescope should be a major objective of the National Space Program, now that sufficiently large rocket booster capability is being developed. 1 A telescope aperture of at least 120 inches is a reasonable goal within the next decade. Technologically, one of the most formidable problems in such an undertaking is that of fabricating and maintaining the figure of the primary mirror of such a telescope to the required tolerance.

An all-electronic scanning spectrometer is described which is capable of scanning the 0.6 to 1 μ spectral region at scan rates of up to 10,200 scans/second at a resolution of better than 15 An image dissector photoelectron multiplier tube is used as the detection device. The minimum detectable signal of the system is less than 1 x 10-6 w cm-2 2-1 at 0.8 μ. The instrument occupies a volume of less than half a cubic foot and is designed for operation in a KC-135 aircraft. Video magnetic tape recording is used, and a digital read-out method has been developed so that the data can be programmed into a computer.

The problem of defining a useful and quantitative measure of the performance of a photo-optical system has engaged the attention of many investigators for the last twenty years or more. The results have not so far been encouraging. The problem is twofold: first, to achieve a means for measuring the output material in an effective quantitative manner and, second, to interpret the results into a measure of real information content. Modern developments in modulation transfer analysis have helped toward achieving success in the first part; it is in the second half of the problem that much work remains to be done. This paper reviews the application of transfer functions to performance measure-ment and prediction, presents the results of some experimental work which has been done, and suggests some possible approaches to the solution of the remaining problems, with the intention of simulating more work in this area.

The first ultraviolet spectrum photographs of stars from a manned spacecraft were taken on July 19, 19661. A lightweight. 70mm camera, equipped with an ultraviolet. lens (UV) and a diffraction grating was hand operated by the astronauts to obtain these spectrograms. The data accumulated. on this and subsequent space flights,enabled the identification of many chemical elements. existing beyond the borders of our solar system and verified several star temperatures2. In future space flight missions, a measure of lunar UV reflectance characteristics are expected to be obtained3. This could significantly bear on the design of space suit visors for moon explorers, safe-guarding them from the dangers of sunburn and eye strain.,

This paper describes the photo-optical instrumentation system presently being implemented for the Biosatellite 30-day mission. This instrumentation has been designed to provide a periodic photographic record of the activities of a restrained Macaca nemestrina primate for the duration of the mission. The 30-day satellites are among the most complex of the unmanned satellites ever built for NASA. The equipment aboard them, including photo-optical equipment, shall not only perform reliably but must also withstand the adverse environments of launch, orbit, re-entry, and recovery while subject to the constraints of minimum power consumption, size, and weight. The effect of these factors is discussed in terms of the system requirements (resolution and contrast by day and night) and constraints (capsule-light levels, cosmic radiation, capsule-space limitations).