It Took Nearly A Century For Mag-Netic Tape Recording To Reach Its Present State-Of-The-Art In Airborne Hardware; A 6 Mhz Mil-E-5400 Vtr Available Off-The Shelf. Wideband Magnetic Recording Really Started In 1952 When Engineers Seriously Began To Develop Video Tape Recorders For Tv Applications. The Rotary Head Technology From These Efforts Resulted In Vtr Products Capable Of Storing And Redroducing The 4.2 Mhz Bandwidth Of Standard Television. Reliable Products Were Developed. Actual Production Hardware Resulted And There Has Been Consistent Refinement, A Wide Selection Of Products And, Lately, Much Cheaper Recorders Available, This Is A Mature Technology Which Slowly Evolved And Found Its Niche In Life.
The Japanese Are Eating The American Electronics Industry Alive! Reasons For This Condition Are Both Numerous And Complex. Most Usually, People Point To The Differential In Labor Costs Between Japan And The U.S. As The Primary Cause, I Question This As A Sole Or Even Primary Aspect Of The Problem.
Gentlemen: 1. Most Of What You Build Is Too Expensive. 2. Most Of What You Build Doesn't Solve The Problem It Was Intended To Solve. 3. Most Of What You Build Is So Unreliable That, If It Was A Consumer Product You Had Bought, You'd Change Brands. 4. Most Of What You Build Is Built In Blind Response To The Customer's Stated Requirements, Instead Of Telling The Customer What He Really Needs, Then Showing Him How To Get It. 5. Most Of What You Build Is Antique. You Squeeze And Squeeze On Old Ideas Trying To Solve New Problems.
The Deputy for Intelligence is supposed to be, in modern Air Force operations, the strong right hand of the Commander. The DI, using various and multiple inputs, is to assess the enemy's capabilities and intentions. The assessments are provided to the Combat Commander for his use in planning tactical operations, utilizing the element of surprise and preventing the enemy's tactical or technical surprise of friendly forces.
The applications of video tape recorders over the past 10 years have been truly incredible. These applications have ranged from the sophisticated broadcast machines of the early sixties to the present handy-dandy, do-it-yourself units for the home. The birth, growth, and maturity of the video taping industry has closely paralleled the skyrocket of broadcast TV. Today, the video tape machine and its partner, the TV video disc, are so essential to the TV industry that they are truly indispensable. It would be hard to imagine a network TV system without its edited tapes of commercials and programs.
Laser video recording is a non-photographic real-time video image data process utilizing special metallic, thin films and a laser to create and read diffraction-limited "holes" in the thin film, at video rates. A two-dimensional ensemble of these "holes" represents an instantly readable and directly viewable replica of the original video image.
The expanding application of video tape recorders in solving in-flight recording problems is the topic for today. What will be presented is an insight into some particular ways in which USAF - here at ADTC -applies video tape recording as a solution to instrumentation problems.
The F-14A is the Navy's newest fighter aircraft. It is designed to achieve air superiority using air-to-air missiles. The aircraft contains a photographic-type mission recorder subsystem which was designed approximately ten years ago for an earlier weapons control system. The increase in the number and complexity of F-14A displays, photographic problems with similiar recorders in the Fleet, and advances in recorder technology have revealed a need to reassess the F-l4A recording requirements.
The Problem - A New Philosophy "Our supply of gold plate is not inexhaustible!" This and similiar statements characterize a new military attitude with regard to hardware acquisition. Limitations placed on military spending have forced us to reevaluate many of our policies in areas of weapons research, development, and acquisition. Efforts to achieve the greatest possible cost effectiveness have forced the military to abandon ideal system developments where attainment of performance was pursued with little consideration of cost. New policies require design to cost wherever possible and advocate use of off-the-shelf hardware as a means of checking sykrocketing development costs. Hardware applied to nonmission-essential roles is particularly subject to this new philosophy. Training equipment is one such application. This paper addresses the impact of these new policies as applied to development and acquisition of a video tape recorder (VTR) for an airborne recording system to be used as an instructional aid for training in the T-37B Aircraft.
The Gunship aircraft operating in South-east Asia have enjoyed a reputation as one of the most successful weapon systems in the Air Foroe. Much of this success has been documented by the Battle Damage Assessment (BDA) facility located at Ubon RTAFB and operated by the 601st Photo Squadron (AAVS).
A flight evaluation of a gated LLLTV light-level television) system for ,SAR (search and rescue) was conducted 4 the Naval Missile Center, Point Mugu. California. The primary purpose of this program was to ascertain the effectiveness of the LLLTV system in acquiring targets (radiating targets, cooperative or noncooperative targets) at night on the ocean surface with the system operating in the passive or active (laser illumination of the target) modes. The second purpose was to compare standard light-signalling devices with a chemiluminescent device (Chemlite) as targets for LLLTV; and to compare their visual (optically unaided) acquisition distances. The third purpose was to de-termine whether or not the standard Navy sea dye, marker, excited by a nitrogen-gas pulsed laser,. would provide a visible light source with sufficient illumination to (1) serve as a visual reference for helicopter night hover, (2) enhance the bility of the searchers to locate a survivor, and (3) be readily acquired by LLLTV.
Reliability and maintainability are important parameters to both user and designer of military equipments. Reliability of electronics equipment can be and has been treated so that nearly any desired level of reliability can be designed in Magnetic recording equipments, however, consist of extensive electro-mechanical systems and the reliability of such systems has frequently not met the expectations of the user or the designer. An even, more frustrating aspect of the equipment from the standpoint of users has been the difficulty of repair of a failure, or plainly, the problem of keeping the equipment on the air". The basic design of magnetic recording equipment, has historically been such that maintenance is difficult.
With the increased applications of television imaging systems in the Department of Defense and Aerospace industries, requirements for recording this information have increased accordingly. Development of television tape recorders usable in airborne applications has essentially paralleled development of these imaging systems and has suffered similar inconsistencies. Because of the typically complex and fragile nature of television recorders, the industry has directed most of its efforts toward commercial and consumer markets and very few equipments are oriented to high environment applications. As high performance airborne video recorder technology is in its infancy, so is an in-depth understanding of these devices by most users. The text philosophy of this paper is to provide a better understanding of rotary head video recorders in a relatively simple but comprehensive manner and to present Echo Science's approach to solving traditional problems common to these devices.
The INSTAVIDEO*recorder was designed and developed as a rugged, portable video recorder for both color and monochrome for the industrial and educational markets. Figure 1 shows the recorder/reproducer portion of the system, and Figure 2 shows it with the cover removed. Recent tests suggest that the machine will operate well in airborne applications. Specifically, it offers low time-base error over wide ranges of temperature, vibration, and acceleration in all attitudes, uses I/2-inch tape on a self-threading reel, can be supplied from batteries or power, and weighs only 17.6 pounds, exclusive of power pack. The present design incorporates both record and playback electronics in the same unit, but substantial advantages could be derived by separating the record unit from the play back system. The latter approach would allow bandwidth extension to 6 MHz from the present 2.7 MHz at -3 dB) at a 43-dB peak-to-peak signal to-rms-noise ratio. However, extension to 3.5 MHz is possible without significant design change.
The efficient use of recording media in a magnetic recorder is the goal of advanced development efforts in longitudinal digital recording at RCA. The rotating head transverse scan (quadraplex) equipments utilized in broadcast television and wideband (4-15 mHz) instrumentation applications provide a prime example of the efficiency possible. The transverse scan equipments conforming to ASA standard C98.6 (1965) half track tape format record a 5.0 mil track with a 2.8 mil guardband which yields 128 tracks per inch of tape. When operating at 25 KBPI in-track packing density, these equipments obtain an area packing density of 3.2x106 bits per square inch. IRIG standard multi-track fixed head equipments conversely yield an area packing density of .07x106 bits per square inch when operating at the same 25 KBPI but only 28 tracks per inch.
The signals from different military video systems range from low bandwidths of 3 MHz or less, upward to perhaps 50 MHz (or even higher) for present and anticipated needs. Unless record times are allowed to extend over many seconds, band-widths of these magnitudes may be needed for use with vidicons and laser recorders of 2500 elements per line (Ref. 1)'. Systems incorporating 8000-line TV tubes are currently under development (Ref. 2). Bousky, et al predict 100 MHz bandwidths as future requirements (Ref. 3). Such wideband systems may be needed either for recording very-high resolution live video, or else in situations where the time available for the recording of any one image is very short.
Since the introduction of the first rotary head videotape recorder in 1956, initially for use in broadcast television recording, videotape recorders have been adapted for use in many other data recording requirements. Some examples of these recording applications are radar, high transfer rate serial instrumentation data, wideband spectrum data, random access file systems for digital and analog image data and many special electro-optical systems. In many cases rotary head recording systems have been used in high environment airborne and even space-borne data systems. Unfortunately, much of the equipment that has been supplied into these hostile environment usages has had a rather poor record of reliability, particularly in the early stages of product evolution. Those products which offered the highest performance in terms of bandwidth, dynamic range and linearity were, until the recent past, without exception, very expensive. A new tape transport approach and scanning method have been developed over the past few years however, which together have resulted in a marked improvement in performance and reliability, significant reduction in size, weight and power, and dramatic initial investment and operating cost savings.All the above mentioned factors enter into user decision making when selecting a recorder system. Performance, reliability, ease of maintenance, and cost of ownership for the three principal categories of rotary scan recording systems will be compared.
Kinescope Recording, the process of photographing a video display with a special motion picture camera was for some years the only method of storing television information. Since its extensive use in the early days of TV broadcasting, the film produced by kinescope recording has usually been described as a "kinescope" even though that term properly refers only to the cathode ray tube from which the film was photographed. The "kinescope" also became associated with indifferent picture quality due to many limitations that existed in early video times. It is the purpose of this paper to review these past limitations and discuss recent developments, with particular thought to airborne applications, which make kinescope recording or VKR's a viable contender for top quality video recording.
Mr. Chairman, Ladies and Gentlemen: I am pleased to have the opportunity to address this seminar and present a chronological description of the developments which have led Teledyne into the Airborne Video Recording field.
In 1970, BBRC started a development program to deliver several video film recorders for the Air Force AN/AVQ-10 Pave Knife Weapon Delivery System. The prime specifications were ten fra es per second recording rate, 450 TV lines resolution, a 400-foot film capacity, physical size and ruggedness.
Historically, Video Kinescope Film Recorders (VKR's) have demonstrated performance that has been notoriously poor. VKR's were especially unsatisfactory when compared to video tape for recording 525 line rate systems for which the video tape was not bandwidth-limited. Recent advances in VKR technology have made it competitive with video tape systems, especially for recording high line rate systems which are now widely deployed and for which the video tape is severely bandwidth-limited. The Super 8mm VKR described here incorporates sophisticated and reliable circuitry to perform the function of expanding or compressing the video dynamic range to fill the density range of the film. Thus, a "flat" scene of low contrast will be expanded to achieve the same density range as a high contrast scene. This circuitry includes automatic gain control, automatic contrast control and gamma correction. Together with the extremely high resolution of the system, this circuitry make possible recordings of heretofore unrealizable quality.
In recent months the Air Force has initiated a request to photograph video displays in their Pave Spike system. Certain constraints were included in this request which dictated the following basic objectives in development of a video film recorder: 1. An optical design which would allow direct film recording of the video display without impairing the observer's view. 2. A mechanical design which would (a) not interfere with the pilot's ejection envelope, (b) provide reasonably easy installation and (c) allow loading and unloading of the magazine without removal of the camera. 3. An electronic design which would provide synchronization of camera operation to the 60 Hz field sync signal available from the video display equipment and automatic recording during laser firing. To satisfy the above objectives, Perkin-Elmer agreed to provide an engineeting evaluation and test unit for initial ground and flight testing. This unit included certain features which are not incorporated in the final production design. The results of the evaluation tests provided specific guidelines for a final design and it is this design which is described in the following text.
The recording of radar information has been of interest to the Air Force for many years. These recordings are used as a method of documenting test activities and evaluating radar systems. Two primary types of recordings are made; magnetic tape recordings of the raw radar si al, which may be replayed at a later time, and film cameras, which take pictures of the radar display itself. Each of these recording techniques has its own peculiar disadvantage.
I would like to discuss briefly some considerations for design and production of a stop-motion analytical projector for analyzing Super 8 film generated in a Super 8 VKR system. Performance specifications for this projector certainly stretch the present state of the art if not exceed it. What are some of the specifications and what do we propose to do in order to meet them.
Certain applications exist in the Air Force today where television type pictorial data is obtained simultaneously from two different sensors and where a direct visual comparison of these sensors is essential. Because basic difficulties exist in attempt-ing such comparison from two separate films run synchronously, it became evident that recording the sensors in side-by-side frames on a single film could be much more effective. Moreover, preliminary exploratory investigation had already shown that laser recording techniques could not only provide the means for such recording, but could also provide the precision, resolution, and latitude to effect real-time 875 line recordings within a super-8 millimeter frame.
Capability specifications of an all solid state laser recorder employing LCIS LRT (Laser Ray Tube) with top of the technology modulation and deflecting components and laser compatible vesicular film medium will be outlined. Discussions follow on the impact of this and other current technology developments on requirements of airborne video recorders and other like systems.
Color images and other multispectral information can be recorded on black-and-white film through the use of a unique spatial carrier for each spectral band. (Ref. 1,2,3,4,5) This paper will describe the technique and its applications and discuss the results of its implementation in a laboratory facsimile system.
The KDI Image Test and Evaluation System (KITES) was designed to assist in the test and evaluation of video systems and was developed for the Air Force under the auspicies of the Avionics Laboratory. In synthesizing a design approach for KITES, it was decided that old-fashioned resolving power would be used as an evaluation parameter, in spite of its shortcomings as an image evaluation criteria. It is a subjective measurement and repeatability between observers can be worse than ±20%. High contrast targets are normally used and hence only "end point" data is obtained, where the square wave target response function approaches zero at the higher spatial frequencies. It is generally believed that MTF/OTF techniques for evaluating images should provide more insight into what hap-pens at the lower spatial frequencies. Futhermore, a good automated technique for measuring MTF/OTF should be possible with electro-optical mea-surement techniques coupled with a computer to plot the final MTF curve and phase curve.
The evaluation of laser recorders, like any other optical system, includes a determination of its spread function or modulation transfer function. Conversely, the design of such systems properly starts with an allotment of the spread function among the various system components (optics, film, electronics, etc.) so the composite effect (the convolution of the component spread functions) yields the desired goal.
The overriding problem in airborne video recording is the preservation of image quality in the reproduced display. Techniques have been developed to maintain and enhance image quality for video kinescope recorders by electronic processing of the video signal. These techniques may be utilized during the recording phase in the interface between the data source and video recorder, and/or during the reproduction phase in the interface between the recorder and display. The image characteristics effected, and the methods of enhancement are described herein, including gamma correction, auto-matic contrast control, black and white level control, aperture correction and bandwidth equalization. Performance characteristics of hardware in which these techniques have been implemented are presented.
We will discuss our unique Disc Recorder/Reproducer System in two parts. First, we will describe the technology and the visual communications capability it portends, impart a description of the unit, provide some background on its development, cover the various modes of operation and provide insight into the parameters of the system for each operational mode. Second, our discussion will cover the technical details of the recorder and its operation and discuss in detail the feasibility studies associated with the stereop-sis and enhanced signal modes.
This experimental study was undertaken to determine the feasibility of correcting apex angle differences in multifaceted rotating mirrors by depositing optical coatings to build up a linear wedge on the spinner facets. Line pitch variations on film caused by apex angle differences in multifaceted mechanical scanners have been a problem within the industry for some time. The correction of these apex angle differences has previously been attempted through electro-optic or acousto-optic laser beam deflectors, with varying degrees of success. For fixed errors, such as exist in a high precision mechanical scanner rotating about a stable spin axis, a passive correction technique is, in many cases, pref-erable, particularly if the technique does not require an increase in the system size, weight, power consumption, or complexity.
A video processor is described which performs a wide range of algorithms on two channels of video. The video is normally generated by two vidicon cameras whose formats are in registration. The spectral response of the two cameras can be chosen to achieve the maximum definition of the subjects of interest. The processor can difference the two channels of information, normalize the difference to either channel, i.e., divide by, and false-color the processed signal by assigning colors to the difference values. The processor thus provides a real-time, highly en-hanced multispectral display for interpretation, and no film handling or developing is required. An added feature is the ability to correct the video for lens fall-off and camera non-uniformities on a 16 X 16 array basis in the format.