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An equipment is described which will automatically locate and then read off data points from CRT traces recorded transversely on 35 mm film. Up to 512 data points may be taken from each trace and the output, presented in binary form on 8 level paper tape is a measurement of the vertical distance of each point from a known base line. It has a print out accuracy of 1 part in 127, and an average sampling rate of 85 points per second.© (1966) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We investigated the effect of different stacking order of the four graphene layer system on the induced band gap when positively charged top and negatively charged back gates are applied to the system. A tight-binding approach within a self-consistent Hartree approximation is used to calculate the induced charges on the different graphene layers. We show that the electric field does not open an energy gap if the multilayer graphene system contains a trilayer part with the ABA Bernal stacking.

Conventional optics normally includes only two types of elements: refractive and reflective. Holographic optics encompasses a third type of element; one whose properties are diffractive in nature. The focus of this paper is to outline the properties of a general computer-based analysis and design tool that is directed to holographic optics. This tool is called the Holographic Optics-Analysis and Design (HOAD) program. The program has been designed to be both user oriented and flexible. Four sections are covered in the paper. They are directed to-wards (1) the operating system (MTS) used to support the HOAD program, (2) the hologram ray tracing programs which form the basis of the program, (3) a general discussion of the HOAD program, and (4) an outline of the techniques of using HOAD. The last section of the paper is directed towards an assessment of where HOAD presently stands and the direction it is going.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A PIONEERING STEP AND REPEAT CAMERARobert E. Lewis*Philip E. Chandler **ABSTRACTBefore commercial cameras were available, a twelve barrel step and repeatcamera was constructed using one light source. Magnification adjustment, plateflatness, azimuthal control, pulsed exposure, grid register, random intercon-nection and also maintenance methods devised are summarised. A matched reduc-tion camera completed the system.1.0 IntroductionThis paper recounts the develop-ment of a step and repeat camera fora microphoto mask system at TeledyneSemiconductor in Mountain View, Cali-fornia. This camera, designed andbuilt in- house, was modified progres-sively over several years; in itsfinal configuration as described atthe end of this paper only the object-ive lenses and three other pieces ofthe original camera were left.The camera was first built andplaced in operation in 1961, when stepand repeat cameras with suitable char-acteristics were not yet commerciallyavailable. For nearly ten yearsthereafter, this was the only step andrepeat camera at Teledyne Semiconduc

The intent of this paper is to summarize the state-of-the-art of acousto-optic devices (A/0 devices) and discuss some of the appli-cations. The paper deals primarily with acousto-optic deflectors and modulators; however, a unique application of using A/0 devices to generate a "traveling lens" is described in Section II.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In the course of evolving a completely new news picture distribution system for the Associated Press, we have developed a facsimile system using laser scanners and dry silver paper. It is believed that a substantial improvement in cost/performance ratio has been achieved. The system features feedback intensity control of a modulatable He-Ne laser, a flat-bed double pass optical system, a galvanometer-driven mirror for horizontal scanning, paper motion for vertical scanning, and oven pro-cessing of the exposed paper. The tone scale is controlled with stable processing conditions and a non-linear amplifier to compensate for the D log E characteristic.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper I am attempting to review the work on o.t.f. that has been carried out by the Optical Design Group at Imperial College, and in the short time that is available I will not be able to discuss many topics in much detail. We are intending to publish several papers on various aspects of o.t.f., and these papers will include more detailed descriptions of particular subjects.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The paper gives some preliminary results of a continuing experimental study of adjacency effect. One of the important variables to consider in evaluating photo-interpretation by human observers is the adjacency effect, such as that resulting from the sharp contrast of black and white areas on a photographic surface. When human observers view a photographic surface on which black and white are adjoining, the adjacency or "edge" effect occurs. They notice a band of greater brightness just before the light area apparently shades into gray and a band of greater darkness just before the apparently gray area shades into greater darkness. Examination by a photometer or other optical instrument shows that these bands of light and dark do not exist and are only apparently present in the pattern. The apparent brighter and darker bands occur at the point of what was first known as the Mach Band effect (1916). The paper is concerned with a quantitative evaluation of the Mach Band effect when brief exposure time, less than .5 seconds is used.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper reexamines laser-excited pulsed dye lasers since they may be advantageous over other types of pulsed lasers in some holographic applications. Of particular interest is the capability of dye lasers to generate sufficient energy per pulse and with sufficient coherence to record holograms. This capability was demonstrated just recently (Ref. 1) and will be discussed in more detail in this paper. The additional capabilities of the dye laser to be frequency tuned throughout the entire visible spectrum and to operate at two or more frequencies have potential importance in holographic contouring and underwater holography. (Dyes can be selected and tuned to match the optimum transmissivity of the working medium.) The selective interaction of dye laser light with living organisms may permit minute dimensional changes to be observed and measured. The low intrinsic cost of the active materials and operational reliability of dye lasers are other desirable features.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Of the two principal areas in which laser and nuclear technology may interact - laser-induced fusion and nuclear-pumped lasers - this paper concerns the latter. The concept involves direct conversion of fission energy, mostly kinetic energy of charged particles (fission fragments), into coherent radiation of optical frequencies. Papers dealing with this subject began to appear around 1961. A review of this earlier work is given in Reference (1).© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The paper concerns the perceptual movement image produced without actual target displacement. The perceptual movement image is variously named the beta movement, phiphenomena, or apparent movement. The production of the movement images depends upon such physical factors as the proper distance between targets, the proper time interval between presentation of the targets, and the target intensities. The influence of these physical conditions on the perceptual movement images and their application are discussed in the paper; specifically, the emphasis is placed on the measurement methods. Psychological research in this area may provide some clues for designing optical instruments.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Mertz and Young introduced the idea of using a Fresnel zone plate as a shadow-casting reticle, or coded aperture, in x-ray astronomy. More recently, considerable progress has been made toward using the zone-plate aperture for gamma-ray imaging in nuclear medicine. The most successful configuration has used an off-axis section of a zone plate in conjunction with a halftone screen. In this paper, we discuss a variety of closely related coded apertures, including an annulus, an inverted zone plate, a spiral zone plate and the Girard grill. In most cases, the technique of grid-coded subtraction is used to suppress the zero-order (DC) background light usually associated with zone-plate imaging. The first application of this technique, reported by Stoner et al., used a sequence of two to four on-axis zone plates. In the present paper it is shown that the method can be extended to other apertures and is also very useful in synthesizing the spatial filters for optical decoding.

This paper constitutes a current status report on the automatic laser tracker being used at Sandia Laboratories' Sled Track Facility. A short review of the need and system description will, be covered, followed by a description of problem areas. Most of the paper will deal with the modifications completed and the results thereof.

In the field of psychology, very few studies have been concerned with the underwater human photo-optical system. The present paper is based upon a review of approximately 300 publications related to the psychological and behavioral analysis of the photo-optical systems of marine and land animals. Some of these publications include discussions of human vision under water and on land. Information obtained from this review can be useful in the planning of needed research programs and in the design of future underwater instrumentation. The present paper concerns the capabilities and limitations in hue and intensity discriminations of various marine and land animals, including man. Emphasis is on the methodological problems in experimental measurement. With respect to animals, instrumental, physiological, and photo-chemical methods are discussed; for humans, psychophysical methods (i.e., methods of limits, of adjustments, and of constant stimuli) are discussed. The major finding of the present review is that marine animals use color and motion stimuli as cues almost exclusively in contrast to land animals who use primarily distance, shape,and size stimuli as cues, although marine and land animals have structurally similar eyes. This dif ference is discussed in relation to a comparison of the perceptual capabilities and limitations of humans in underwater and land situations. Psychological research in this area may help in the development of reliable underwater illumination methods and the design of underwater instrumentation.© (1966) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Derek Morgan of Rank Precision Industries presented a paper to the SPIE meeting last year on Traffic Engineering. This paper reports on advances in the technology since that time. Review of Previous State of the Art. A. We use glass fiber optic bundles that will withstand the high temp-eratures of high intensity light sources. B. Fiber optic bundles are produced in the form of a harness; 1 input, up to 250 output tails. C. Arranging the output tails in a pegboard allows fixed messages to be brightly displayed as dots of light.

The subject of this paper is a simulation technique which has been developed to evaluate the performance of standard scan (525 line) TV contrast trackers in the laboratory. The simulation, developed in conjunction with a comparative flight test of TV contrast trackers conducted at Holloman AFB, New Mexico, makes use of a basic technique similar to the "instant replay." Video tape recordings are made with appropriate video instru-ipentat.:_minstalled in a C-130 "flying laboratory" as the aircraft simulates attack passes against various ground targets. The recorded video is then played back into a contrast tracker in the laboratory to evaluate the contrast tracker performance. This simulation technique is discussed in detail in the paper along with a description of the technique employed to demonstrate the accuracy and validity of the simulation results. In addition, the paper includes a brief discussion of future simulation requirements.© (1969) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper concerns a simple, underwater camera which in use is operated flooded with water. All of its parts including lens, shutter, and photographic film are exposed to and operate in direct contact with the water in which the camera is immersed. As the paper progresses, I'll first describe the camera, then show some underwater photographs made with it, and finally discuss some problems we had at the beginning of its use and tell how we overcame the problems.© (1971) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The sea change experienced in a large under-water acoustic energy source, placed on the ocean floor at a 300-fathom depth, is discussed as it is examined from the surface three years later by reactivation of an installed closed-circuit video link. The author recapitulates an earlier paper on this subject that was presented at the SPIE Seminar of February 1968 (published in the Seminar Proceedings, vol. 12, pp. 73-80), updates the background of the initial ocean emplacement, and discusses the sea changes in the submerged structure and instrumentation. He illustrates the various areas of interest by videotape recordings. Many questions have arisen concerning the effects of long-term deep submergence on various parts of the video' apparatus including the camera, camera viewport, the camera pan and tilt unit, the lighting unit, and the long cable. This paper discusses some of these questions.© (1971) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Numerous current studies of traffic flow are being carried out via aerial photography. Aerial photography has dominated other means of traffic flow data acquisition, primarily because it provides the instantaneous state of all traffic over a very wide metropolitan area. Sequences of aerial photographs taken at predetermined intervals, for instance one-second intervals, provide discrete data from which the continuous traffic flow may be reconstructed. Vehicular trajectories and various traffic flow parameters are determined from this data. This paper describes ,the photographic techniques, data reduction, and computer interface methods which were developed at the Institute of Transportation and Traffic Engineering, University of California, Los Angeles. Photography is carried out with a camera of 70mm format, utilizing a 3 8mm lens. Data reduction employs the 29E Film Reading System, and its associated 282E Telecordex, both manufactured by Computer Industries. Computer pro-grams have been developed and imple-mented, using the IBM 7094 computer. To eliminate the human operator, computer-controlled film-scanning and data reduction are under development. This method reduces data reduction time to 5-10% of the time required by the method above. It employs the Programmable Film Reader (PFR-3), manufactured by Information International, Inc. This paper describes the photogram-metric techniques employed in locating a vehicle in a ground coordinate system. It also describes pattern recognition techniques, whereby the behaviour of each vehicle traversing the area under study can be determined.© (1969) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Xeroradiographic and radiographic film image analysis through application of the radiographic modulation transfer function defined in this paper is a powerful analytical tool. This tool has been found to predict spatial and densitometric characteristics of an x-ray image for an arbitrary set of input object exposures and contrast variations with sufficient accuracy to allow meaningful comparisons of different types of radiographic imaging systems. This paper presents a simple computerized technique for the derivation of the radiographic modulation transfer function from the image of a knife edge test object. Techniques used for assessing the degree of system linearity over the output response range of interest and the role of the system phase response are also presented. Typical xeroradiographic, screened and unscreened film radiographic modulation transfer functions derived with the program are compared and discussed in the conclusion to the paper.© (1971) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

THE PHOTO- OPTICAL SYSTEMS OF MARINE ANIMALSBy Kiyoe MizusawaChrysler Corporation Space DivisionAbstractIn a previous paper by the author(Ref. i$) it was concluded that marineanimals primarily use color and motionas cues for visual performance almostexclusively, in contrast to land ani-mals who use shape, size and distancestimuli as cues, although they havestructurally similar eyes. This paperexplains to what extent marine animalsuse color and motion stimuli as op-posed to shape, size and distance ascues in marine environment. In thepaper the behavioral measurementsmethod was emphasized.IntroductionThis paper is an extension of apaper presented by the author at theSeminar of "Underwater Photo -Optics,"sponsored by the U. S. Naval MissileCenter Pt. Mugu and the Society ofPhoto -optical Instrumentation Engi-neers (Ref. l8). In the previouspaper, it was concluded that marineanimals primarily use color and motionas cues for visual performance almostexclusively in contrast to land ani-mals who use shape, size and distancestimuli as cues, although they havestructurally similar eyes. This paperexplains to what extent marine animalsuse color and motion stimuli as opposedto shape, size and distance as cues inmarine environment.The first objective of the pre-vious paper was to interpret the cap-abilities and limitations of man'svisual systems underwater in relationto fish based upon phylogenetic com

The paramount importance of the hologram recording process has been recognized since the pioneering work of Gabor (Ref. 1). It is evident that information lost in the recording step of holography cannot be recovered subsequently. Therefore, it is essential to carry out this step in an optimum manner, retaining as much of the original object information as possible. Since its critical na-ture was widely appreciated, it is not surprising that the effects of this recording process have been the subject of well over one hundred published papers, innumerable talks, and much unreported research. As a result of this substantial effort, many aspects of hologram recording materials and practices are now well understood. However, there remain numerous questions, a few of which will become evident in the course of this paper.© (1971) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Xeroradiography is the technology for recording radiographic images without the need for any chemical processing whatsoever. To make an image a selenium photoreceptor, or plate, is charged to a uniform surface potential on the order of 1000 volts. When this photoreceptor is exposed to x-rays, its surface charge is depleted by photoconduction in amounts proportional to the radiation intensity striking it. A residual potential pattern which is a shadow graph of the object being x-rayed is then formed. After exposure, the electrostatic image on the plate is developed by a powder cloud technique in which charged, pigmented particles are blown over the plate and adhere to it in the pattern of the image. This powder or toner is the ink which defines the image. Following development, the toner is transferred to paper and fixed into a permanent image by low temperature heat fusing. The purpose of this paper is to present the principles of zero radiography, to describe practical equipment utilizing these principles for x-ray imaging in the medical and industrial fields, and to show some examples of the types of images produced by the system.

Two years ago at the tenth SPIE Symposium I presented a paper (Ref. 1) which illustrated some of the work JPL has been doing in the development of hardware and techniques for processing of the Ranger and Mariner pictures. It is the purpose of this paper to bring you up to date on our more recent activities.© (1967) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

With the advancement of long duration of manned space flight and prolonged submergence of the nuclear powered submarine, research on the effects of atmospheric contaminants on human visual performance has been increased. Atmospheric ions could cause changes in efficiency of visual performance. The present paper is concerned with systematic review of articles on the effect of atmospheric ions on visual performances. In general, exposure to certain amount of negative ions enhance certain aspects of visual parameters such as brightness discrimination and motion detection, while certain amounts of positive ions deteriorate most visual performances. The need for the control of air ions in maintaining optimal environmental conditions has been suggested in this paper.© (1970) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Photography from space is limited in results by both the parameters of the photographic system and the atmosphere. As better photographic systems are developed, atmospheric effects give the ultimate limit to the quality of photography of the earth from space. The principal atmospheric effects of contrast degradation and turbulence are considered. A mathematical basis for the selection of critical photographic variables to optimize contrast is given. Computerized calculations of the ground resolution obtainable from space for various turbulence states are also given. This paper is based on two previously puolished papers from the SPIE JOURNAL (Vol. 1, No. 2 and Vol. 6, No. 1). aecause of the complicated equations and numerous illustrations in these papers, they are reproduced here to give the reader the advantage of more detail than could be obtained from the summary talk given at the Tokyo Seminar. Fragmentary experimental data from space operations indicates that the conclusions of these papers are essentially correct.© (1970) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Within the past year, several papers have been presented concerning the advent of a new device for real-time non-contact thermal imaging of microscopic targets. This device, the BM-50 IR Microscanner has since been utilized in several new and interesting areas of non-destructive testing and it is the purpose of this paper to discuss these new applications and to project sore areas which show future promise.© (1972) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper concerns a simple and inexpensive method for computing the polychromatic MTF of an optical system whose performance is determined essentially by longitudinal chromatic aberration. This method employs the results of wave optics computation and therefore retains high accuracy regardless of whether image quality is governed primarily by diffraction, geometric aberrations, or any combination thereof. We believe the analysis methods outlined in this paper will provide a useful engineering tool to the systems engineer who wishes some reasonably accurate insight into the effect of chromatic aberration on MTF tradeoffs. For lenses intended for high-acuity aerial photography, as a general rule, chromatic aberration will seriously limit MTF performance for focal lengths longer than 6 inches.© (1968) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper deals with a program of research in which the techniques and fundamental limitations of the restoration of degraded images is receiving study. The research program includes all forms of image degradation but this paper is concerned only with the case of degradation of the type encountered in looking up through the atmosphere with a large ground based telescope.© (1967) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The purpose of this paper is to report experimental laser induced Raman and fluorescence measurements of combustion exhausts. The work was motivated by a desire to develop an optical means of performing gas analysis of combustion products of aircraft turbine engines in the field which does not require the placement of a physical probe in the exhaust volume and which could be fully automated.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Holographic interferometry is firmly established as a versatile tool for the research scientist and the practical engineer. The principal applications of the method up to now have been in the general area of non-destructive testing of various mechanical structures. The purpose of this paper is to review the recent advances in the state-of-the-art of holographic interferometry and to discuss the potential of the technique for biomedical applications.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Fiber optic image couplers are essential components in many types of image intensifier tubes. The paper described the various forms of couplers for such applications and some of the steps leading to their development. The properties and capabilities of image couplers were discussed along with test methods and specifications, also examples of intensifier tubes and systems employing their components.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Summary In the past few years it has been shownthat OPS analysis techniques can simplifya wide range of automatic inspection prob-lems. The technique can be used to auto- matically inspect textile, steel, paper, plastics, glass and a variety of industrial parts. They can also be used to sort live cells or to analyze chest X -rays. (Refs. 5 and 6.)In general, there is a considerable eco-nomic benefit to using OPS techniques forthese applications, and in many cases, auto-mated inspection would not otherwise beeconomically feasible. The same holds truefor photogrammetric applications. Wherelarge amounts of imagery are to be analyzed(ERTS imagery for instance), then the simplifications afforded by OPS sampling techniques are worth consideration. Acknowledgment s The area correlation results were ob- tained under Contract DAAK02 -73 -C -0367 with the U. S. Army Engineering Topographic Laboratories, Ft. Belvoir, Virginia. The defocussed imagery was supplied by the ItekCorporation Model Facility. A portion ofthe graded imagery was supplied by JackMaier of the Rome Air Development Center.

In this paper we review the design and operation of tunable lasers which have outputs in the visible and ultraviolet portions of the spectrum, and which employ organic dyes as amplifying media. The em-phasis will be on continuously operating lasers, and in considering the generation of UV radiation we will restrict our attention to non-linear sum-frequency generation using a tunable visible laser as the fundamental light source.

The power spectrum of a time varying signal may be realized using optical techniques by first converting the temporal variations to corresponding spatial patterns, then illuminating the spatial pattern with coherent, collimated light and observing the far field diffraction pattern. The light intensity distribution in the diffraction pattern is directly equivalent to the power distribution in the spectrum of the original signal (Ref.1). This paper describes the implementation and perform-ance of a real time, coherent optical spectrum analyzer that uses magnetic tape recording to convert temporal variations to corresponding spatial magnetic patterns, and uses the longitudinal Kerr magneto-optic effect to couple these magnetic patterns to a coherent illumination source. A magneto-optic transducer was developed that replicates the magnetic patterns from magnetic tape by contact printing and has magnetic and optical properties required to achieve a sufficiently large Kerr effect for practical applications.

The continued pressure for increased function complexity and more functions per package has led the semiconductor industry into a new generation of processing technology. The success of these complex functions in the marketplace (calculators, watches, home enter-tainment, etc.) has accelerated the need for very high volume imple-mentation of these process developments. Therefore, the semiconductor manufacturer has entered a new era of extremely precise process control coupled with a need for programming each process to the optimum yield performance. In addition to these quality measures, modern semi-conductor economics require practi-cal cost effective automation. This paper will cover the problems as-sociated with process optimization and automation of the photoresist facility. It will disclose the results of a survey of what industry needs in equipment to best attain the conditions. After the results are covered, you will be presented with Cobilt's answers to those needs.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In the field of Automotive Safety there is apparently an absence of a solution to the problem of sensing spacial intensity data in a rapidly scanned field of view and processing this data in real time. DBA Systems, Inc. has developed and is fabricating a system that will, under program control, direct a non-storage photo-emissive device beam to a discrete X, Y address location. Intensity information at and around this point is then transferred to memory for real time processing. The Automatic Programmable Film Reader (APFR) presents itself as a highly useful system when applied to the field of Automotive Safety. The APFR locates up to 30 points of interest on a single frame of film. The system then tracks and stores the new locations of these points in the ensuing frames. Tracking, locating, and advancing of film is accomplished fully automatically under program control and does so with an accuracy of less than 10 microns. The total time required to track and store the locations of the full complement of points per frame is 10 seconds. The ability to track points of interest within a given field of view in real time with a non-storage camera is further enhanced by a choice of optics and projection heads enabling the operator to observe 16mm, 35mm or 4" x 5" cut film records. In addition to the storage of location information on each frame, the frame itself is magnified and projected onto a viewing screen for visual observance by the operator. This paper describes the solution to the problems of inaccurate and inefficient film analysis. The solution lies in the replacement of human "eyes" with an optical sensor capable of digitizing information and transferring the information at a high throughput rate to a computer for real time processing.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Optical data processing is one of the most powerful and versatile processing tools to emerge in recent years. Numerous texts, conferences, and special issues of journals have been devoted to its many accomplishments. There are many types of optical processors: some use non-coherent rather than a coherent light source, while others use non-holographic rather than holographic processing methods. The hybrid optical processor described in this paper can be partitioned into two sections. One is a conventional coherent optical processor while the second section is a digital minicomputer. These two sections communicate via a special purpose digital interface. With this configuration, the best features of both optical and digital processing are retained.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An earlier paper (Ref. 1) described the setting of focus in aerial cameras by locating the plane giving maximum modulation at the spatial frequency corresponding to the low contrast resolving power. A modified apparatus has been applied to determine the area weighted average modulation over the whole field (AWAM) as a function of focus, and hence to locate the best compromise focus having regard to field curvature, etc., and to the asymmetry almost invariably present in production lenses. For four types of lens, the best AWAM focus was not significantly changed by the presence of typical amounts of asymmetry. The agreement between the foci determined by the single frequency measurements and those determined by photographic picture quality was within acceptable limits.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

* Over the last five years NASA has supported ranging on the lunarsurface with a ruby laser. l' 2 The laser was constructed by theKORAD Corporation and is installed at the McDonald Observatoryin Texas.The laser emits a 20 joule - 30 nanosecond pulse. Of the returningsignal, collected by the McDonald telescope, approximately on_photoelectron is produced. The photomultiplier on the telescope isrange gated to reduce the background. Signal averaging techniques are used. With this whole system one can measure distance fromMcDonald Observatory to the moon to an accuracy of X10 centimeters.Experiments are aimed at determining more precisely the orbit of the moon. Better knowledge of the orbit of the moon can be used todetermine more accurately the shape of the earth. Future experi-ments were described in which laser ranging would be done simul-taneously from different points on the earth, i. e. , different stations.These measurements would afford a means of predicting continentaldrifts and early prediction of earthquakes. Ideally, it would be betterto have a more intense laser and a laser which emitted in the greenwhere photomultipliers are more sensitive. Funding for these neces-sary improvements have not been forthcoming.*Note: This summary was prepared by R. F. Wuerker, Chairman ofthe Laser Seminar, since an abstract or paper was not received by

Optical spectral analysis is finding wider application in data processing. The major advantages of the technique are very high speed and high resolution (Refs. 1,2,3). As an example, the laser beam system considered in this paper can continuously record a signal of several MHz bandwidth with no loss of data. The laser beam recorder may be considered as the input channel of a computer. The data are stored on film in a compact raster format in analog form and can place about a half million samples in the aperture of the optical computer. Because the optical analyzer or computer produces output based upon this large data sample, the resolution of the system is greatly enhanced.

The last decade has seen an increasing inter-est in developing alternatives to manual stereocompilation. These new methods have ranged from electronic cross-correlation to optical cross-correlation and match filtering (Ref. 1-3). This paper discusses a technique of generating a complete set of contours using a relatively simple optical apparatus. Over-lapping stereophotographs are coherently summed using a Mach-Zehnder Interferometer. For vertical photography the y-parallax can be removed by proper orientation of the film plates and the only remaining x-parallax is due to terrain elevation differences. This parallax will result in a grating-like structure that can be bandpass filtered in the Fourier Transform plane to pass some given grating spacing and the corresponding parallax. The filtered image will contain a constant parallax contour, which for vertical photography is a constant height contour. Since the grating-like structure is not sinudoidal, higher order frequencies will be present and harmonic frequencies corresponding to multiples of the parallax associated with the filter frequency will also be present and produce additional contour fringes at a reduced modulation in the image.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The challenge facing the mapping community today is the effective utilization of increasingly large volumes of aerial photography and other data to provide topographic information in the form of line maps, orthophotomaps, specialized products or individual responses to decision makers and other users in a timely manner. Automation of rapid screening techniques to determine the suitability of aerial photography for further processing represents an important aspect of this problem. This paper discusses the use of data from the optical power spectrum for cloud screening of aerial photography with emphasis on the computer processing of signals from a segmented spatial frequency plane detector in a coherent optical system. It is assumed that optical samples from aerial photographic patterns will have optical power spectra with attributes representitive of the patterns which can be electronically detected and classified by statistical pattern recognition techniques. This hybrid approach provides an advantageous combination of the speed of the optical Fourier transform with the flexibility of digital processing which leads to a simple, efficient system with the potential for screening aerial photography at very rapid rates.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Since much of the information presented in this paper is my interpretation of earth observation developments during the past twenty years, it is well that I offer some qualifications. I am an engineer of the "old school" with degrees in aeronautical and electrical engineering. I say old school because it was hammered into my head at Georgia Tech that engineers do useful things or they starve. I have been concerned during my twenty-five years of R&D experience in airborne instrumentation developments that the output of results of practical use to society has been minimal. I have become more enthused in the past nine years from my participation in the development of multispectral scanning and discrimination techniques. I believe we have finally developed a useful new remote sensing tool. As you might imagine I am biased toward aircraft as a widely useful earth observation platform for optical scanners. However, I see the merit of other platforms and I am an advocate of using appropriate tools for a particular job.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The overall thrust for development of Night Vision Systems has been to provide equipment which will satisfy the high performance requirements of the modern Army while keeping both acquisition and maintenance cost at the low level necessary to allow high density utilization, This thrust has been pursued by placing emphasis on modular configuration, which allow common use of major. components such as standard, image. tubes, lens systems, and power supplies. Other papers presented during this seminar have already covered, in great detail, image tube and optical assembly. performance. Therefore, I will cover only field applications, present status and development programs.

Today, we have a new generation of spectroscopic tools that have such extremely high resolution capabilities that we are no longer limited by the so called "instrumental linewidth." In today's optical spectroscopy, the limit is more likely to be the natural or, in certain cases, the transit-time linewidth. To perform ultrahigh resolution spectroscopy one generally requires a tunable laser with a narrow spectral width, a means of reducing any mechanism that tends to broaden the spectral line under observation (e. g. , Doppler and collisional broadening) and, finally, a precise method of calibrating the tuning range of the laser. This paper will review the design of low-FM jitter lasers that can be precisely tuned, line-narrowing techniques including saturation, molecular beam and two-photon methods; and possible schemes for calibrating precisely the visible and infrared regions of the electromagnetic spectrum. Recent data in ultrahigh resolution spectroscopy will be presented.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

There are many lenses, particularly those used in photographic applications, which are focused for different object positions, forming images at different magnifications. Moving the entire lens assembly along the lens axis while the object or image locations are unchanged is termed a conjugate shift, and because the lens aberration correction is well maintained for a small conjugate shift for most lenses, this has become the traditional focusing technique. Newly designed, compact telephoto and wide angle lenses, however, do not have a stability of correction over a sufficiently large range of conjugate distances to satisfy the needs of the photographer, and thus employ various mechanical techniques to compensate for the aberration change. In addition to these "extreme" lenses, the question of how much normal lenses degrade in performance over a large conjugate change, say m'.0 to m'.-.3 arises, followed by the question of whether normal lenses can be designed which will be uniformly corrected over such large ranges. This paper discusses the limitations of some popular lens types, and shows some methods which can be employed to achieve the desired uniformity.© (1974) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.