• POLICY ISSUES IN CABLE COMMUNICATIONS

      Hinchman, Walter R.; Office of Telecommunications Policy (International Foundation for Telemetering, 1972-10)
      Cable communications constitutes a complex and dynamic new medium for both selective and mass distribution of entertainment and information programming, as well as new information exchange services. The complexity of technical, operational, social, political, and economic issues relating to cable probably exceeds that of any electronic communications development to date. Fortunately, there are relevant experiences from many other communications operations -- common carriers, broadcasters, the publishing industry, etc. -- which provide insights into the probable evolution of cable communications and into the many policy issues which exist or will arise. By carefully selecting from among several options for industry structure and integration, it should be possible to achieve -with minimal detailed regulation -- a cable communications industry which encourages diversity of information and entertainment services, guarantees access by all responsible interests, avoids excesses of monopoly powers, and is truly responsive to public needs and interests. That, at least, is the objective of the Administration’s current Cabinet-level policy review.
    • SPECIAL SERVICES TO NEIGHBORHOOD AND HOME: A COMMUNITY TELECOMMUNICATION DEMONSTRATION CONCEPT

      Hiibner, Calvin W.; Siegel, Alan R.; Department of Housing and Urban Development (International Foundation for Telemetering, 1972-10)
      This paper discusses the potential impact of cable television or broadband communications on the urban environment. It suggests that the availability of improved two-way communications between individuals and public institutions presents new opportunities for delivering social services in a cost effective manner. Also, that this mode of delivery may be superior in other ways to our present system of delivery. Unanswered questions do remain on the use of technology for this purpose, however, and to answer these questions an experimental demonstration in one or more “real” cities is suggested so that future urban telecommunications systems can be designed with social service delivery in mind.
    • CHANNELIZATION AND CHANNEL MONITORING IN FDMA COMMUNICATIONS

      Gagliardi, R. M.; University of Southern California (International Foundation for Telemetering, 1972-10)
      In this paper the concept of spacecraft self-regulation of downlink power output is investigated for a hypothetical frequency division multiple access (FDMA) communication net. In this operation channels are filtered off (channelization) and monitored to determine those channels that are inactive; i.e., not transmitting. The results of the activity survey are then used to control channel gain in the spacecraft and regulate the drive power into the output amplifier. In this way, available repeater power normally not used during periods of low activity can be redistributed over the active channels to improve their performance. For maximum improvement, this requires not only adjustment of the individual channel gains, but removal of the inactive channels from the limiter. Equations are developed which are useful for system design and aid in the evaluation of resulting system performance and assessment of feasibility of implementation.
    • BIOTELEMETRY IN THE 1970’S

      Rader, D. R.; University of Southern California (International Foundation for Telemetering, 1972-10)
      A date cannot be pinpointed for the concept of using telemetry for acquiring biological data; however, it is known that the birth of biotelemetry in the form of hardware occurred about 1921--with the report of a heart sound transmitter. Biotelemetry matured only slightly from the twenties to the early fifties. During the fifties and sixties large amounts of money were administered through the money pipeline of the federal government. As a consequence, the growth during this period was bath rapid and grotesque, with tentacles reaching into scores of industrial and educational institutions. Duplication of efforts was quite common during this period and hundreds of miniature biotelemetry systems were built, but results deriving from practical application were quite limited. During the last few years, much of the chaff was shucked from this new growth, a root system developed, and biotelemetry found limited use as a tool in clinical medicine and in medical research. In the past biotelemetry has not lived up to the expectations. What about the future--will it really occupy an important place in clinical medicine and medical research? What is the economic outlook--how many jobs will it support? Which areas will require new talent? And, finally, what are the most common problems and haw can they be solved?
    • U.S. AIR FORCE TELEMETRY IN THE 1970’S

      Hargrove, W. W.; Norton Air Force Base (International Foundation for Telemetering, 1972-10)
      The telemetry systems used by the U.S. Air Force in the ‘70’s must be highly reliable, flexible, possess growth potential and meet the requirements of operational realism, An attempt must he made to provision the basic weapon system design for the required telemetry hardware in order to prevent the tested version from incurring a penalty due to its subsequent incorporation. The components associated with future U.S. Air Force telemetry systems will be lighter, smaller, consume less power, withstand more severe environments, and cost much less than those of the past.
    • IMPLANTABLE ULTRASONIC BLOOD FLOWMETERS

      Meindl, J. D.; Stanford University (International Foundation for Telemetering, 1972-10)
      Accurate measurement of pulsatile blood flow can be achieved on a chronic basis in research animals through the use of totally implantable ultrasonic flowmeters. The continuous wave Doppler flowmeter provides an attractive technique for measurement of flow velocity at a particular location such as the center of the lumen; the pulsed Doppler flowmeter is attractive for measurement of flow velocity distribution or profile across the vessel and lumen diameter, and hence volume flow. Both instruments can be electronically precalibrated and exhibit no baseline or scale factor changes during chronic experiments. Custom designed silicon monolithic integrated circuits offer significant advantages in reduced size and power drain as well as improved reliability in these instruments.
    • DATA NETWORKS AND POLICY: AN INTRODUCTION

      Enslow, Philip H. Jr; U.S. Army Signal Corps (International Foundation for Telemetering, 1972-10)
      The data and computer communications services, including data networks, to be made available in the future will depend not only upon the needs and desires of the users; but also upon the economic, social, and regulatory factors that must be considered. The Office of Telecommunications Policy in the Executive Office of the President has the responsibility for recommending to the President national policies and goals in this area as well as telecommunications in general.
    • USE OF IMPLANTED TELEMETRY IN VASCULAR RESEARCH

      Rader, R. D.; Stevens, C. M.; Henry, J. P.; Meehan, J. P.; University of Southern California (International Foundation for Telemetering, 1972-10)
      This paper outlines a program to study the development and progression of essential hypertension in dogs through the use of totally implanted telemetry. In light of the role that social interaction may play in the development of hypertension in man, emphasis is placed on inducing and monitoring the effects of social strain in the dog: and because of the role the kidney may play in the development of hypertension, a model for renal flow has been developed. The effect that pharmacological concentrations of vasodilator and vasoconstrictor agents have on renal hemodynamics are evaluated. Preliminary data from investigations on the renal hemodynamics of unrestrained dogs in various stages of psychophysiological stress are presented.
    • FIBER OPTICS COMMUNICATIONS

      Somekh, S.; Yariv, A.; California Institute of Technology (International Foundation for Telemetering, 1972-10)
      The transfer of information in the form of light waves via an optical fiber waveguide is discussed. Small size and weight together with high information rate capability make the fibers attractive for various types of communications systems. Description of channel characteristics such as attenuation and bandwidth is given, and possible input and output devices are examined.
    • 10-MICROMETER BAND COMMUNICATION TERMINALS IN SPACE

      McAVOY, N.; Goddard Space Flight Center (International Foundation for Telemetering, 1972-10)
      10-micrometer band communication systems using CO2 lasers for space to space links are discussed. Particular emphasis is on low earth orbiting earth observation satellites to geosynchronous satellites at high data rate. Four key technology areas are discussed: Wideband mixers for Doppler tracking; tunable laser local oscillators; high data rate modulators; laser transmitters.
    • A 10.6 MICROMETER LASER COMMUNICATION SYSTEM FOR TERRESTRIAL USE

      Goodwin, F. E.; Hughes Research Laboratories (International Foundation for Telemetering, 1972-10)
      This paper reports the development of an experimental type 10.6 μm laser communication system consisting of a transmitting terminal and a receiving terminal designed to operate one way over a nominal five mile terrestrial path. The system will provide a 5 Mbit/sec digital data channel utilizing intra-cavity optical frequency modulation, or frequency shift keying modulation format. It uses optical heterodyne detection with a mercury cadmium telluride detector operating at a temperature of 77°K and an i.f. frequency of 30 MHz. Since the system operates from fixed (non-mobile) terminals, acquisition and alignment procedures are simplified. Predicted performance in rain and fog is discussed and compared with a limited amount of actual data.
    • A NEW VHF-INTERFEROMETER WITH THREE STEERABLE HIGH-GAIN-ANTENNAS FOR SATELLITE-TRACKING

      Fogy, W.; German Aero-Space-Research Establishment (International Foundation for Telemetering, 1972-10)
      The German-Central-Ground-Station near Weilheim, Bavaria, called Z-DBS, operates now on VHF-Telemetry and Telecommand. Its monopulse-autotrack-subsystem measures one way doppler datas and medium-precise (~0,25° RMS) direction angular (AZ,EL) datas. For precise orbital tracking the station will now be completed by a VHF-Interferometer with three steerable high-gain-antennas, using the angular information of the existing system for initial acquisition and ambiguity resolution. Such a system is applicable to track most near-earth-satellites in orbit without needing a global network even with a relatively low percentage of contact time because of its large angular- and distance-coverage from one topos. The interferometer, now under construction, will be ready for operation at the end of 1973. The present paper gives a brief description of the parameter requirements, the system itself and the methods used to overcome the very high technical difficulties. The total residual direction error is predicted not to exceed (10÷15)”, including nearby ground reflexions but excluding residual athmospheric propagation effects. High side-lobe-suppression-antennas with extremly stable phase characteristics as well as a 3-channel-piloting-receiver-system are used to make the antenna’s difference-phase errors small enough and to eliminate phase changes throughout long cables and receivers. A computer operates the whole system to a high degree of automacy and evaluates and smoothes the direction datas.
    • DATA QUALITY ASSURANCE IN A SHIPBOARD COMPUTERCONTROLLED TELEMETRY SYSTEM

      Baggot, H. E.; Interstate Electronics Corporation (International Foundation for Telemetering, 1972-10)
      This paper describes a computer-controlled telemetry system used as a shipboard telemetry station for U. S. Navy Poseidon FBM weapon system testing. Built into the equipment are rather sophisticated automatic tests. These tests allow expected. equipment performance to be verified under conditions very nearly like those to be encountered during the data receiving mission. Also built into the equipment are provisions for real-time display and quick-look playback capability. These provisions allow evaluation and analysis of the test results within a few hours of the operation.
    • IMPACT OF SOLAR CALIBRATION ON TELEMETRY SYSTEM TESTING AND CHECKOUT

      Crane, Williams S.; Pickett, Robert B.; ITT-Federal Electric Corporation (International Foundation for Telemetering, 1972-10)
      The advent of solar calibration techniques has resulted in a drim--tic reduction in the time required to conduct telemetry antenna system measurements. Solar calibration provides a rapid, simple and accurate means of determining antenna system performance in the field environment. A program of solar calibration was instituted two years ago at the SAMTEC Western Test Range (WTR) as a basis for calibration,.trouble shooting, operational planning and determining premission “Go/No-go” status. Solar testing has assisted the site personnel in decreasing the time required for system performance tests, preventative maintenance, premission checkout and trouble isolation. The results obtained are more accurate than the laboratory or antenna field measurements for the determination of either gain or system noise temperature independently. In most cases, measurements provide absolute values within ±1 db accuracy. The Figure of Merit (M = G/T(s)) is now a required data item for some missions and is requested by the range user to assist in his data evaluation.
    • APPLICATION OF RANGE COMMANDERS COUNCIL DOCUMENT 118-71 TEST METHODS TO RANGE MANAGEMENT-SAMTEC

      Radom, Stanley R.; Vandenberg Air Force Base (International Foundation for Telemetering, 1972-10)
      Range management techniques utilized by the SAMTEC enable telemetry system and subsystems to be validated for operational support readiness. Application of test methods from Range Commanders council Document 118-71 are described for solar calibration of the telemetry receiving system, PCM bit error rate and FM noise power ratio testing. Limitations of noise power ratio testing is described including need for additional range user performance requirements. The use of test results provides SAMTEC range management with a near realtime certification of telemetry system performance accuracies. System performance levels are established which provide a “red flag” indicator to alert range management that systems are below the norms expected. Application of the test methods and the use of the red flag provides the SAMTEC range management the decision making information required to employ minimal telemetry systems and manpower resources in the effective achievement of range user program support requirements. These test methods will be used to establish the data base for scoring the range technical support contractors performance incentive fee. An additional benefit of the test methods is their application for the test and acceptance of new telemetry systems and subsystem.
    • STATISTICAL DYNAMICS OF A FIRST-ORDER PHASE-LOCKED LOOP

      Mengali, U.; Univerità di Pisa (International Foundation for Telemetering, 1972-10)
      The paper deals with a procedure for studying the transient behavior of a first-order phase-locked loop in the presence of noise. This procedure requires the numerical solution of an ordinary differential equation. Excellent agreement has been found between theoretical results and those obtained via computer simulation.
    • MANAGEMENT OF A MAGNETIC TAPE DUBBING AND EVALUATION STATION

      McKelvey, George R.; Schoeck, Kenneth O.; ITT-Federal Electric Corporation; Vandenberg Air Force Base (International Foundation for Telemetering, 1972-10)
      An instrumentation magnetic tape dubbing and evaluation station is being established at SAMTEC in an effort to improve the quality of data provided to the range users. An analysis of the problems associated with the dubbing process along with the development, configuration and operation of the station are presented.
    • RECENT DEVELOPMENT RESULTS ON THE HELIOS S-BAND COMMAND RECEIVER

      Heynisch, B.; AEG-TELEFUNKEN (International Foundation for Telemetering, 1972-10)
      By joint effort of the US and West Germany a Sunprobe will be launched by 1974 named HELIOS. In the Telecommunications Subsystem the Telecommand Receiver has a keyrole as Experiments have to be switched up to 2 AU distance from earth. The input power at the Receiver Equipment input terminal is -147 dbm with SNR of 6 db in 2 BL(o) = 32,5 Hz Loop Bandwidth. To achieve this sensitivity a Receiver in Phaselocked loop techniques with a low noise Preamplifier had to be developed. In cooperation and with consultance of well known US-Scientists it was possible to design and develope the S-Band Receiver up to the Qualifikation Model in less than two years. This report shall give a survey over concept and design of the receiver and some special experiences during development and integration tests.
    • A SINGLE CHANNEL COMMAND DETECTOR FOR DEEP SPACE MISSIONS

      Knapp, Siegbert; AEG-TELEFUNKEN Laboratories (International Foundation for Telemetering, 1972-10)
      AEG-TELEFUNKEN has developed a Single Channel Command Detector which will be used in the solar probe HELIOS. This command detector demodulates command data, PSK-modulated on a subcarrier with a symbol error-probability of less than 1x10^-5 at an input signal to noise ratio of 13,2 db per symbol-length. The command detector consists of two succeessive second-order phase locked loops and a matched filter. The subcarrier synchronizer loop tracks the 512 Hz subcarrier, the bitsynchronizer loop performs data-synchronisation and in contrast to former space concepts, requires no additional power. The matched filter correlates the input signal and its estimate, generated by the subcarrier synchronizer-loop. The integration over exact dataperiods is dumped by the bitsyncpulse. This command detector enables the HELIOS Receiver chain to demodulate command data with less than 1 error in 100 000 symbols over a distance of ~ 300 mill. km. Due to sophisticated digital decoding of the HELIOS Decoder, this error-probability results in 1 false command being executed in 64 years.
    • AIRBORNE VISIBLE LASER OPTICAL COMMUNICATION EXPERIMENT

      Randall, J. L.; Marshall Space Flight Center (International Foundation for Telemetering, 1972-10)
      A series of optical communication experiments between a high altitude aircraft at 18.3 km (60,000 ft) and a ground station are planned by NASA in the summer of 1972. The basic concept is that an optical tracker and transmitter will be located in each terminal. The aircraft transceiver consists of a 5-mW HeNe laser transmitter with a 30-megabit (Mbit) modulator. The ground station beacon is an argon laser operating at 488 mn. A separate pulsed laser radar is used for initial acquisition. The objective of the experiment is to obtain engineering data on the precision tracking and communication system performance at both terminals. Atmospheric effects on the system performance are of prime importance.