• The Use of Binary Cyclic Codes in the Generation of Two Other Classes of High Security Codes

      Brothman, A.; Horowitz, L. M.; Halpern, S. J.; Brothman, E. H.; Reiser, R. D.; Transitel International Corporation (International Foundation for Telemetering, 1965-05)
    • An Advanced Integral Missile Evaluation System

      Mayo-Wells, Wilfrid J. (International Foundation for Telemetering, 1965-05)
    • Standards Re-evaluation for Wideband Magnetic Tape Recording

      Ratner, Vic A.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
    • Application of a Telemetry System using DSB-AM Sub-Carriers

      Roche, A. O.; Dynatronics, Inc. (International Foundation for Telemetering, 1965-05)
      The advantages of the DSB-AM subcarrier for wideband telemetry requirements have been discussed in previous papers. The purpose of this paper is to consider the specific performance of an FM telemetry r-f link when modulated by a frequency multiplex of DSB subcarriers. The performance is evaluated by constructing an appropriate model of the subcarrier multiplex based on a predicted noise power spectrum at the r-f demodulator output. The model is used to specify the individual subcarrier amplitude values that constitute the baseband signal, which will modulate the FM transmitter. The carrier power required to produce a useful signal-to-noise ratio at the outputs of the individual subcarrier demodulators is considered in general. The relationship between the degree of transmitter deviation, receiver bandwidth and the carrier power is derived. The carrier power required for operation over typical test range distances is determined in terms of the appropriate variables. The performance of two specific examples is calculated to illustrate the use of the several formulae that are derived. The examples also serve to relate and compare the performance of the DSB system configurations to the more traditional applications. Finally, the advantage of using increased r-f bandwidth is discussed.
    • F. M. Capture Performance - Characterization and Measurement

      Baghdady, Elie J.; Gutwein, Joseph M.; ADCOM, Inc. (International Foundation for Telemetering, 1965-05)
      The effects of interference and capture in FM reception are reviewed for the purpose of determining the basis for characterizing and measuring the capture performance of FM receivers. Capture performance criteria and performance measurement techniques are proposed for application to FM telemetry receiver evaluation.
    • Evaluation of an Expanded FM/FM Baseband Structure

      Campbell, E. B.; Herbert, W. R.; Electro-Mechanical Research, Inc. (International Foundation for Telemetering, 1965-05)
      An experimental evaluation program was undertaken to investigate the feasibility of expanding the IRIG (Inter-Range Instrumentation Group) FM/FM baseband. The results of the evaluation indicate that with typical field equipment, three higher-frequency proportional-bandwidth channels can be added to the baseband while maintaining adequate system performance.
    • A New Approach to Effective Digital Filter Design

      Duncan, P. H.; Douglas Aircraft Company (International Foundation for Telemetering, 1965-05)
      In this paper the effect of modifying digital filter weights derived on a least squares error basis through multiplication by certain weighting functions is investigated. It is shown that this approach amounts to adopting frequency resolution as a filter performance criterion, in a manner analogous to resolution in spectral estimates along the lines of Blackman and Tukey. Weight formulation using the method is very simple, and working transfer functions are easily estimated without computation. Simple, effective designs are presented for low, high and band-pass (or band-stop) filters of the "cosine" or in-phase type, for cosine "low low-pass" and "sampling" filters, and for "sine" or quadrature "sampling" filters, as well as differentiators.
    • Frequency Spectrum of an FM/FM Signal

      Holt, J. C.; Douglas Aircraft Company (International Foundation for Telemetering, 1965-05)
      Several authors have attempted to derive a mathematical model that will describe the frequency spectrum of a FM/FM signal. However, to this author's knowledge, none of the mathematical models that have been published is valid when the carrier is modulated by more than one subcarrier. In this paper an expression for a FM/FM signal is derived that is valid when IRIG specifications are applied. Then this expression is manipulated into a form that will yield the frequency spectrum when the carrier is modulated by any number of subcarriers. Then an illustration of a two subcarrier frequency spectrum is presented.
    • International Telemetering Conference Proceedings, Volume 01 (1965)

      Unknown author (International Foundation for Telemetering, 1965-05)
    • High "G" UHF Telemetry for Gun-Launched Sounding Probes

      Cruickshank, William J.; Ballistic Research Laboratories (International Foundation for Telemetering, 1965-05)
      The development of a UHF telemetry system that will withstand the high shock (50,000 g) of gun launched vertical sounding probes is described. The associated development of a ground based automatic angle and range tracking and receiving system using a modified AN/GMD-1A Rawin set is also presented.
    • Rocket Trajectory Analysis from Telemetered Acceleration and Attitude Data

      Cooper, Oscar L.; Research Foundation, Oklahoma State University (International Foundation for Telemetering, 1965-05)
      Double integration of the longitudinal acceleration of a sounding rocket is useful as a simple means of determining its trajectory. Reasonably accurate altitude calculations can be made by this method except when surface winds alter the launch angle of the rocket. Surface wind velocity corrections can be introduced to correct velocity and position information in the horizontal direction, but accurate wind correction data is difficult to obtain for all rockets. A special solar aspect sensor was designed to be used with a commercially available magnetic aspect sensor for rocket attitude determination. This attitude data allows the longitudinal acceleration to be broken more accurately into three vector components. A feasibility study of the aspect system was made using three Aerobee-150 rockets. A digital computer trajectory program was written to utilize aspect and acceleration data for trajectory analysis. It is evident that rocket attitude data is a useful supplement to the longitudinal acceleration data for trajectory determination. More accurate magnetic aspect data is necessary, however, to refine the longitudinal acceleration technique.
    • Matched Filter Systems in Rising Noise Spectrums

      Halpern, P.; Electro-Mechanical Research (International Foundation for Telemetering, 1965-05)
      It is common knowledge that the matched filters for signals in white noise have impulse responses whose time duration is exactly as long as that of the input signal. Nothing can be gained by extending the response of the matched filters to longer than one bit unless (1) the signal source is coded, or (2) the noise spectrum is rising or at least is other than white-Gaussian-ergodic. This paper discusses means of improving bit error rates without coding the source. There are essentially two ways of extending the integration time of the matched filters, each of which offers an improvement in signal-to-noise ratio. The first way is to extend the response directly to more than one bit but constrain the filter to give zero or some small pre-assigned intersymbol crosstalk. The second way is to build matched filters for multiple bits. Both techniques can be used simultaneously; i.e., matched filters can be constructed for bit patterns, and the responses can be extended to longer than the baud to which the filters are matched. Once again this extension is done under the constrain of zero or little crosstalk. In this paper, the matched filters for several examples are expanded in a rapidly converging series, each term of which is identifiable with a known network. For the cases where the shape of the noise is not known analytically, an experimental technique is given for determining sufficient statistics of the noise so that the optimum matched filters can be designed.
    • Recent Developments Pertaining to Solid-State S-Band Transmitters

      Slone, Sam; Fjeldsteld, Norman B.; Monitor Systems (International Foundation for Telemetering, 1965-05)
      This paper discusses the performance of some recent R. F. power transistors as frequency multipliers and relates this information to their use in solid state V. H. F. and U. H. F. Telemetry Transmitters. The step-recovery diode is - similarly discussed. Both devices are shown to have great promise for ultimately lowering the complexity, size, and price of Solid State S Band and L Band Telemetry Transmitters.
    • Analysis of FM/FM Transmission Line Distortion

      Mohnkern, Gerald L.; N.A.S.A. (International Foundation for Telemetering, 1965-05)
      An IBM 1620 computer was programmed to evaluate the effects which the variation of propagation velocity and attenuation in coaxial cables has on a frequency modulated carrier. For a nine mile length of RG-8A/U the distortion of 70kc modulation on a 1 mc carrier was severe, while for a 10 mc carrier the distortion was negligible. A typical system using 4, 6, and 9 mc carriers on a single cable was evaluated.
    • Telemetering Physiologic Data from Athletes

      Rose, Kenneth D.; University of Nebraska (International Foundation for Telemetering, 1965-05)
      Employing a team composed of physicians, electrical engineers, and specialists in physical education, significant dynamic physiological data has been gathered by means of radiotelemetry from athletes undergoing strenuous effort, participating in team sports, and from spectators viewing football games. Using a transistorized A.M.-F.M. transmitter carried in a padded compartment strapped comfortably onto the low back and weighing 30 oz. complete, ECG, pulse, temperature and respiration signals have been transmitted for distances up to 500 yards. The multiple technical problems surrounding distance telemetering of physiological information during active and vigorous muscular effort are discussed. Somatic muscle interference, the most troublesome artefact in dynamic electrocardiography, has been successfully circumvented by instantaneous recording of data from the momentarily inactive subject. Application of computer techniques to the analysis of exercise electrocardiograms must await procedural improvement and standardization and collection of adequate data on which to base valid programming.
    • Design and Performance of a New S-Band Transmitter

      Swartley, Richard H.; Eitel-McCullough, Inc. (International Foundation for Telemetering, 1965-05)
      This paper describes a telemetry transmitter designed for the 2.2-2.3 Gc band. Design philosophy followed to achieve minimum size, wide deviation capability, high reliability and high efficiency are discussed in detail. The paper presents extensive measured data to indicate achievement of design goals set by IRIG 106-60 and ARTC-34. Construction details of the transmitter are illustrated.
    • Conditioning and Recovery of Aircraft Position Signals Through an Existing Data Link

      Kashar, A.; Kearfott Division, General Precision Aerospace Group (International Foundation for Telemetering, 1965-05)
      A Signal Data Converter system records aircraft present po t on and altitude data on film and also displays this data in a ground shelter, allowing for real time surveillance by a ground observer. This is accomplished by adapting a unique digital data transmission system to an existing infrared video data link.
    • Design Considerations in Pre-D Receiving and Recording Equipment

      Swanson, E. E.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
      Design factors to be considered in wide band Pre-D recording and playback equipment for usage in a versatile Pre-D system are presented. These design factors are introduced in a discussion of both the down-translator and up-translator. The mechanisms which produce spurious outputs from the up-translator and the effects caused by these spurious outputs are treated in detail. The extension of Pre-D techniques to FM Electronics equipment is covered.
    • A Wideband UHF Transmitter for Space Applications

      Digiovanni, J. J.; Murphy, R. T.; Lockheed Missiles and Space Division (International Foundation for Telemetering, 1965-05)
      This paper describes the design and performance of a frequency-modulated 10watt S-band transmitter. Analogue frequency response is in excess of 7 Mc and digital signals at rates up to 10 megabits per second are transmitted satisfactorily. This extra wideband transmitter, ruggedized for space applications, utilizes a solid state exciter for signal generation, a traveling wave tube amplifier for power amplification, and a solid state traveling wave tube power supply that will withstand critical atmospheric pressures. A detailed analysis of rf bandwidth requirements and the state of the semiconductor art at the time of transmitter design resulted in the exciter taking the form of a 70 Mc voltage controlled oscillator whose output is amplified and converted to the S-band output frequency by means of broadband varactor harmonic generators. Production versions of this transmitter have consistently demonstrated satisfactory orbital operation. Laboratory data has indicated a minimum rf power output of 10 watts at base-plate temperatures ranging from -35° to +75° Centigrade. Baseband response is from 10 cycles to more than 7 Mc at ±6 Mc frequency deviation.
    • An Adaptable Spacecraft Telemetry System

      Maxwell, Marvin S.; Silverman, Joseph R.; Czarcinski, Eugene A.; Goddard Space Flight Center (International Foundation for Telemetering, 1965-05)
      Because of the limitations of hardwired telemetry systems, existing spacecraft are denied the capability of revising their sampling structure, their sampling rates, or the experiments and/or test points to be sampled. A centralized system to provide these capabilities is described in this paper. This system is called the Flexible Automatic Computer Telemetry System (FACTS). As initially conceived, the FACTS, through the use of a stored program, will be able to sample a large number of channels with great flexibility in sampling rates, sampling structure and the selection of experiments and/or test points. This paper outlines the basic spacecraft and ground station system and illustrates the flexibility which can be achieved with it. Selected diagrams are given along with a description of the operation of the various units in the system.