• A HIGH SPEED AIRBORNE DATA ACQUISITION AND CONTROL SYSTEM WITH AN INTEGRATED DIGITAL COMPUTER

      Trover, William F.; Teledyne Controls Company (International Foundation for Telemetering, 1973-10)
      AIFTDS-4000 has been developed as a modularly expandable instrumentation and control system primarily for use in aircraft and system flight test. The bidirectional data processing capacity of Remote Multiplexer/Demultiplexer Unit, however, permits the system to be applied to data processing and control loop functions as well as the classical role of a data gathering system. The basic system was developed for NASA-FRC under three different contracts; NAS4-1848 (the ACS and RMDU’s), NAS4-1940 (the integrated signal conditioner cards) and, NAS4-1943 (the expanded test set). The system comprises Airborne Hardware, Ground Support Equipment and Software. The Airborne Hardware is divided into two major elements; The Airborne Computing System (ACS), and the Remote Multiplexer/Demultiplexer Unit (RMDU). Ground Support Equipment is presently restricted to the ACS Test Set (ACS/TS) which permits total checkout of the ACS without the RMDU’s or checkout of the full AIFTDS, as well as performing the function of an autonomous mini-data reduction ground station and the Portable Address Generator which permits testing of one RMDU (or one zone of the airplane) without the ACS or the ACS/TS. Software may be grouped into System Checkout and Diagnostic Software, Flight Test Program Software and Quick Look/Reduction Software. The prototype AIFTDS-4000 was qualified in two stages; the RMDU was qualified in October 1972 with the ACS qualified in April 1973. The Expanded Test Set and supporting software were delivered in May 1973.
    • THE INFLUENCE OF CARRIER FREQUENCY ON SNR FOR FM SYSTEMS

      Monson J. E.; Harvey Mudd College (International Foundation for Telemetering, 1973-10)
      The influence of carrier frequency on broadband signal-to-noise ratio is derived for a frequency modulated tape recording system. Optimum signal-to-noise performance occurs at the value of carrier frequency where the carrier-to-noise ratio is falling at 6 dB/octave. Signal-to-noise ratio is relatively insensitive to changes in carrier frequency about the optimum value.
    • INTERFEROMETER SIGNAL DEMODULATION IMPROVES TRACKING SENSITIVITY

      Cooper, William K.; New Mexico State University (International Foundation for Telemetering, 1973-10)
      A considerable improvement in signal to noise ratio has been achieved in narrow band interferometer trackers by demodulating the telemetry signal prior to the final stage of i-f amplification. This system has an effective signal bandwidth much greater than the noise bandwidth. Signal to noise improvements of 10 dB are typical.
    • International Telemetering Conference Proceedings, Volume 09 (1973)

      International Foundation for Telemetering, 1973-10
    • MEASURING TERRESTRIAL RADIO FREQUENCY INTERFERENCE AT ORBIT ALTITUDES

      Bayol, Martin E.; Locke, Paul A.; National Scientific Laboratories, Inc. (International Foundation for Telemetering, 1973-10)
      Satellite systems, by virtue of their large terrestrial fields of view, may be exposed to a great many man-made radio signals the aggregate effects of which can be deleterious to satellite receivers. An experiment has been designed to measure and characterize such man-made interference at orbital altitudes. The experiment, as designed, requires dedicated hardware on a spacecraft of specified orbit and will measure (within the frequency range of 400 MHz to 12.4 GHz) peak levels of interference in cells dimensioned in space, time, and frequency. The experiment will provide data indicative of some of the statistical characteristics of interference levels at satellite orbital altitudes and will provide designers of satellite communications links with new facilities for the prediction and prevention of interference problems, and should provide a considerable data base for use in long range planning of spectrum utilization.
    • MECHANICAL DESIGN CONSIDERATIONS FOR A PROJECTILE TM

      Williams, Don, JR.; Sandia Laboratories (International Foundation for Telemetering, 1973-10)
      The mechanical packaging necessary to protect electronic packages from the gun firing accelerations is the key to a successful telemetry system. All components and wires must be given structural support, usually by the use of potting materials. Where the accelerations come from and two successful packaging methods are described.
    • MILITARY COMMUNICATION SATELLITES

      Wall, Virgil W.; The Aerospace Corporation (International Foundation for Telemetering, 1973-10)
    • A MULTI-PURPOSE, DUAL-CHANNEL MODEM FOR C/No THRESHOLD

      Baghdady, Elie J.; Info Systems (International Foundation for Telemetering, 1973-10)
      A description is given of a newly developed modem based on the synthesis of a constant-envelope quadra-phase signal with dual-channel frequencydivision multiplexing of analogvoice with data, data with data, time code With data, ranging signal with d:Ata, etc. The technique is capable of providing low-threshold operation down to carrier power-to-(noice power density) ratios, about 40 db, and includes a built-in, on-line measurement and display of the C/N(o) for quantitative performance monitoring purposes.
    • MULTIMEGABIT OPERATION MULTIPLEXER SYSTEM

      Giri, Ronald R.; Maxwell, Marvin S.; Radiation; Goddard Space Flight Center (International Foundation for Telemetering, 1973-10)
      The Multimegabit Operation Multiplexer System (MOMS) is a high data rate PCM telemetry unit capable of sampling and encoding 60 scanning radiometer and 4 vidicon channels at 250 kilosamples/second and 5 megasamples/second, respectively. This sampling capacity plus the 7-bit quantization requires a total throughput rate of 40 megasamples/second and 280 megabits/second. To produce these rates efficiently, the system was divided into a pair of identical 140-megabit blocks. A low-power 20-MHz analog multiplexer and analog-to-digital converter were developed together with a video sample-and-hold that features an aperture time error of less than 50 picoseconds. Breadboard testing of these basic building blocks confirmed the design prediction that the total system would consume 27 watts of power. Two 140-megabit output ports are suitable for quadraphase modulation.
    • MULTISTATE ANALOG AND DIGITAL INTEGRATED CIRCUITS

      Abraham, George; US Naval Research Laboratory (International Foundation for Telemetering, 1973-10)
      Several independent physical phenomena in unipolar and bipolar semiconductor pn junction devices and integrated structures lead to voltage and current-controlled negative resistance without the use of external feedback. These include avalanche breakdown, quantum mechanical tunneling, and minority carrier storage. Two complementary types of negative resistances may be utilized as a basis for generating multistable energy levels. The number of stable states and their relative spacings can be readily varied. Without negative resistance interaction, M+1 stable states can be generated where M is the number of negative resistance devices involved. With negative resistance interactions, additional multistability occurs, resulting in a total number of (M+1) + (M-1)!stable states. S-S, N-N, and S-N interactions are analyzed. In the latter case, complementary negative resistances can be made to annihilate each other. Multistate tunnel and avalanche negative resistances have been made to occur in single devices resulting in tristable, quadristable and higher order energy levels. Variable radix counters, oscillators, frequency dividers, and high density memory elements have been fabricated both as hybrid and monolithic integrated circuits.
    • THE NEED TO MEASURE MAN-MADE RADIATION FROM ORBIT FOR SPECTRUM MANAGEMENT

      Eckerman, Jerome; Wolff, Edward A.; National Aeronautics and Space Administration (International Foundation for Telemetering, 1973-10)
    • A NEW ERA IN WORLDWIDE TACTICAL COMMUNICATIONS

      Reid, Charles E. Jr; Naval Electronic Systems Command (International Foundation for Telemetering, 1973-10)
      The Fleet Satellite Communication System (FLEETSATCOM) now under development will provide the first U. S. military satellites designed from the start as operational transponders for tactical communications with and among mobile users. FLEETSATCOM is a logical outgrowth of earlier experimental projects, principally the Tactical Satellite Communication (TACSATCOM) project of the late 1960’s. When the globe-girdling system goes operational in calendar year 1976 it will quite literally revolutionize both Air Force and Navy tactical communications by providing availability and reliability of over-the-horizon communications that can never be matched by conventional high-frequency circuits.
    • NEW MAJORITY-LOGIC DECODABLE CODES

      Chen, C.L. (International Foundation for Telemetering, 1973-10)
      A method of the construction of majority-logic decodable codes is presented. Many of the codes constructed are more efficient than any other comparable majority-logic decodable codes previously known.
    • ON DETERMINATION OF OPTIMAL ACCUMULATION TIME IN PARTICLE FLUX REGISTRATION

      Babkin, V. F.; Institute for Space Research (International Foundation for Telemetering, 1973-10)
      Poisson particle flux is considered which intensity is a random process. The equations are presented for the construction of the intensity realization estimate corresponding to the minimum of a mean-square reconstruction error. The condition is derived the filfulment of which assures the existence of the optimal accumulation time minimising the reconstruction error. The calculation results are given to illustrate the dependence of a mean-square reconstruction error on the accumulation time.
    • Optran® AN INFRARED LED TRANSCEIVER FOR DATA COMMUNICATIONS

      Meyer, Andrew W.; Harting, Stephen W.; National Aeronautics and Space Administration (International Foundation for Telemetering, 1973-10)
      The following discussion reviews operating experience with a non-coherent infrared (IR) optical data link at several installations in the United States. Optran is a commercial digital data link, manufactured by Computer Transmission Corporation, for computer-to-computer or computer-to-terminal data transfer applications. It uses a nonlasing gallium arsenide diode as the transmitter and a silicon diode as the receiver. Simple optics collimate the transmitter output and focus the captured receive energy on the receiver diode. A digital interface unit at each terminal end presents a standard interface to business equipment and encodes/decodes data from the optical head.
    • A PCM DATA SEQUENCE CONTROLLER

      Sandia Laboratories; Johnson, Charles S. (International Foundation for Telemetering, 1973-10)
      The PCM Data Sequence Controller described in this paper is used to interface a memory-controlled PCM encoder with a plated wire memory to form a unique digital data compression and storage system. The memory-controlled PCM encoder is used to select formats and convert input analog data channels into a PCM bit stream which is both transmitted and stored in a plated wire memory. The encoder is also used to retrieve information from the plated wire memory and retransmit it. The system provides both temporary and permanent data storage for the telemetering of data in a severe environment.
    • PERFORMANCE OF A 350-Mb/s ADAPTIVE EQUALIZER

      Ryan, Carl R.; Stilwell, James H.; Motorola Inc. (International Foundation for Telemetering, 1973-10)
      This paper applies baseband adaptive equalization techniques to rf multipath and transmitter/receiver distortions. Included are test results comparing 350-Mb/s adaptive equalized and unequalized receivers. These comparisons are made with distortion typically encountered in a high data-rate line-of-sight microwave system such as demodulator quadrature errors, demodulator phase offset errors, and moderate rf multipath distortion. The design and construction techniques are also illustrated.
    • PLANETARY PROGRAM DATA SYSTEMS STANDARDS

      Glahn, Earl W.; Planatary Programs Data Systems Working Group (International Foundation for Telemetering, 1973-10)
    • PRINCIPLES AND HEAD CHARACTERISTICS IN VHF RECORDING

      Krey, K. H.; Lieberman, A. G.; Harry Diamond Laboratories; University of MD (International Foundation for Telemetering, 1973-10)
      Concepts of VHF analog magnetic recording are discussed; problem areas are reviewed; and solutions are outlined. Attention is drawn to the conductive-gap-spacer recording head. The unique field contours of this recording head with Alfesil pole faces are analyzed in relation to the recording of very short wavelengths. The field gradients of the unloaded head are computed for various conditions such as maximum magnetization depths, positions in the tape coating, and gap lengths. Comparison of the driven-gap-spacer head using Alfesil pole faces with the ferrite driven-gap-spacer head and the conventional ring-core head shows the Alfesil type to be the most effective for a-c bias VHF recording at very short wavelengths. Problems associated with short-wavelength recording and reproduction are reviewed. In spite of good short-wavelengths capabilities of the Alfesil head, the requirement for a high head-to-tape speed continues to be mandatory to minimize wavelength reproduction losses.
    • A PROGRAMMABLE SAMPLING FORMAT TELEMETRY SYSTEM

      Peterson, Max B.; Johns Hopkins University (International Foundation for Telemetering, 1973-10)
      This paper describes the programmable sampling format telemetry system to be used by the near-earth Small Astronomy Satellite-C (SAS-C) and possible future SAS missions. The concept of the programmable sampling format is introduced and the features of the system are illustrated by an example. The SAS-C telemetry system is described at the block diagram level and redundancy of the system is discussed briefly.