• An Advanced Integral Missile Evaluation System

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

      Ratner, Vic A.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
    • 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.
    • 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.
    • Subminiature Inductive Transducers used with High Carrier Frequencies

      Straugh, H.; Associated Engineering, Ltd. (International Foundation for Telemetering, 1965-05)
      This paper describes the development and construction of subminiature inductive transducers which can be operated with carrier frequencies up to 400 Kcs. Two types have been developed for operation at 150°C which are able to withstand an acceleration of 2000g, and a high-temperature (600°C) transducer is now in the final stage of development. The body of the low-temperature transducer is made of high-temperature epoxy resin, and that of the high-temperature transducer of ceramic material. Iron wire is used as core material to reduce eddy current losses. The dimensions of the transducers are 0.25 inch diameter and 0.5 inch long, and 0.125 inch diameter and 0.25 inch long, including terminations. A linear displacement of the armature material can be measured at distances up to 0.01 inch, and because of the high carrier frequency, the vibration of this armature can be up to 30 Kcs. Both ferrous and non-ferrous armature material can be used for displacement measurement. The inductive transducers have been used to measure piston movement at right angles to the cylinder axis in an internal combustion engine, in conjunction with a lead-out system. Tests using a telemetry system (radio link) are now being carried out. Details of the construction and performance are described and future development discussed. The use of the inductive transducer as a pressure transducer is also mentioned.
    • Flexible Communication System for Saturn

      Bruni, Donald J.; Davis, Donald G.; Dynaplex Corporation; N.A.S.A. (International Foundation for Telemetering, 1965-05)
    • 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.
    • 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.
    • Telemetry for 250,000-G Gun Environment

      Finger, Daniel W.; Harry Diamond Laboratories (International Foundation for Telemetering, 1965-05)
      Techniques for packaging telemetry components and systems to withstand gun launch accelerations up to 250,000-g are discussed, and the necessary and sufficient conditions for survival are established. The principal requirements are that all voids be eliminated from the package and that encapsulating resins be adequately contained. The ultra-high-g projectiles used in hypervelocity research for which these telemeters were designed are briefly described. In addition, a brief description is given of high-g telemetry systems used in the gun-fired rockets and projectiles of project HARP.
    • A Class of Digital Transducers Utilizing Magnetic Recording

      Pear, Charles B.; Radiation, Inc. (International Foundation for Telemetering, 1965-05)
      The need for direct digital transducers has been recognized for some time but remains largely unsatisfied. Magnetic recording could be applied for many applications. In this paper the techniques, capabilities and limitations of magnetic recording for measurement purposes are discussed including resolution and flux responsive readout methods. Some of the classes of variables which might be measured are outlined.
    • 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.
    • Research and Development Work on Personal Telemetry Systems

      Marko, Adolf R.; Wright-Patterson Air Force Base (International Foundation for Telemetering, 1965-05)
    • 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.
    • Communications and Command for a Nuclear Lunar Power Plant

      Morris, Vernon B., Jr.; Hanson, William A.; Somers, G. William; Westinghouse Defense and Space Center (International Foundation for Telemetering, 1965-05)
      Extensive lunar exploration will require the establishment of relatively long-term lunar bases. The power demands and the high fuel transportation costs to support these bases will necessitate the utilization of nuclear power plants. In the following paper, the lunar exploration base is briefly described. The economics of electrical power production on the Moon are discussed and the need for a nuclear power plant is established. A power plant configuration is shown. Communications and command requirements are presented and the communications and command system is described.
    • 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.
    • 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.
    • Optimization of Potentiometric Type Pressure Transducers

      Welsh, Luther; Marks, Eugene A.; Bourns, Inc. (International Foundation for Telemetering, 1965-05)
      Potentiometric pressure transducer designs can be optimized to allow application of a given model or family to a very wide range of pressures with consistently low static error band. Analytical and empirical design relationships are developed and correlated to suggest specific optimization techniques.
    • A Multiple-Beam Scanning Circular Array

      Chadwick, George G.; Glass, John C.; Hill, Jerome E.; Radiation Systems, Inc. (International Foundation for Telemetering, 1965-05)
      The geometry of the cylindrical array has always been appealing to system designers because of its ability to provide 360° of coverage. A technique will be discussed which allows a cylindrical array to provide high-resolution coverage over 360° of azimuth angle. When used as a scanning array, a beam may be swept through 360° by using any of the numerous techniques available for scanning a linear array. When used to provide multiple beams, an array of N elements is excited by N isolated inputs. Each input corresponds to a beam in a selected direction; all of the N beams being disposed uniformly over 360° of azimuth angle. In both the instance of the scanning array and the multiple-beam array, the resolution achieved is comparable to that available from a planar aperture of the same height and with a length equal to that of the cylinder diameter. The theory of operation for the cylindrical array is discussed in abridged form. Data are also presented for experimental four-, eight-, and sixteen-element cylindrical arrays.