• Frequency Diversity for UHF Telemetry

      Lilienkamp, Hugh; Naval Avionics Facility (International Foundation for Telemetering, 1969-09)
      This paper describes the function and design of the CV-2138 (XAN-1) UHF Down Converter developed at the Naval Avionics Facility, Indianapolis, Indiana. This unit is part of the Navy's Tartar, Terrier, Talos missile UHF telemetry/miss-distance information (MDI) system AN/SKQ-2 (XAN-1) now under development at this Facility. The converter, a dual-channel unit, receives signals in the 2200-2290 MHz and 1760-to-1850 MHz bands, and produces IF's of 240-330 MHz and 110-200 MHz respectively. The 1960 MHz local oscillator (LO) frequency, common to both channels, is supplied from a single source.
    • Frequency Diversity for UHF Telemetry

      Kinkead, W. K.; General Electric Company (International Foundation for Telemetering, 1969-09)
      The use of frequency diversity to allow substantial airborne antenna simplification for L and S band telemetry is described. The system is particularly useful on large, spin stabilized vehicles where omni-directional antenna coverage is required. Typical antenna patterns with and without diversity are presented. A systems block diagram showing dual receivers and diversity combiner is also described. A weight tradeoff is presented for diversity versus non-diversity, with vehicle diameter (at the antenna location) as the variable. It is shown that, at S band, for diameters in excess of about 5 in., frequency diversity represents a favorable approach.
    • A High Power Versatile Feed System for Communications Satellite Usage

      Hurlburt, Roderic W.; Reiser, Lloyd L.; Yaminy, Roger R.; Radiation Systems, Incorporated (International Foundation for Telemetering, 1969-09)
      The high power versatile feed system for communications satellite usage is of the three-channel monopulse type capable of simultaneous operation over the receiving frequency band of 3700 to 4200 MHz and the transmitting frequency band of 5925 to 6425 MHz. The feed system provides an on-axis transmit beam for the upper frequency range and three-channel monopulse tracking and receiving outputs for the lower frequency range. These simultaneous transmit and receive functions are orthogonally polarized. The feed system consists of a multi-element aperture array with an associated remote polarization control panel. The system is capable of processing transmitted signals of power levels up to 12 kw for the purpose of satellite command and data transmission. It is also capable of processing the relative azimuth and elevation error signals for satellite tracking. The feed system is suitable for primary focal point excitation of parabolic reflectors (F/D between .45 and .6), and for dual reflector or Cassegrainian systems. The sum and difference mode of operation are precisely controlled with a front aperture to provide the proper illumination functions for the particular reflector systems, thus achieving high system efficiencies and correspondingly high G/T ratios.
    • The High Speed Tape Transport

      Isabeau, John G.; Vogel, Charles A.; Newell Industries, Inc. (International Foundation for Telemetering, 1969-09)
      The Newell tape transport principle is used in instrumentation recorders to currently provide upwards of 56 minutes of recording with 15 MHz bandwidth. Bandwidth several times as wide are definitely feasible. The main characteristic of the tape transport is that it permits precise tape handling at speeds up to several thousand inches per second. The paper discusses the results of research on the basic transport system: the phenomenon of progression at the capstan-tape interface, the mechanism of tape flow to and from the reel and around the capstan. The behavior of capstan tires at high speed and the dynamic response of tapes are discussed. The paper is based on considerable experimental data. Several models of high speed machines are shown.
    • International Telemetering Conference Proceedings, Volume 05 (1969)

      International Foundation for Telemetering, 1969-09
    • IRIG Telemetry Standards 1969

      Reynolds, R. Stanton; Sandia Laboratories (International Foundation for Telemetering, 1969-09)
    • Low Cost Water Quality Monitoring by Radio Telemetry

      Woffinden, D. S.; Kartchner, A. D.; Utah Water Research Laboratory, USU (International Foundation for Telemetering, 1969-09)
      A radio telemetry water quality monitoring system has been designed and constructed at the Utah Water Research Laboratory (UWRL). The system consists of a central base station at the laboratory and remote field stations located in the river to be studied. The remote field stations operate in the stand-by mode until interrogated from the central base station. Each station is capable of monitoring dissolved oxygen (D. O.), hydrogen ion concentration (pH), electrical conductivity, and temperature. Other variables could be monitored by using appropriate sensors. The prime features that characterize the UWRL system are low cost and relatively small size. These are both realized through the use of printed circuit boards and integrated circuit amplifiers. The remote station is small enough to be portable and can be installed either permanently or temporarily at almost any river location with a minimum of effort. Such a system, costing about $3,000 per field site, will make feasible the monitoring of water quality at points which previously were uneconomical to investigate.
    • MAP, A Modular Design Concept for Recoverable Scientific Rocket-Borne Experiments

      Wright, W. W.; Southwest Center for Advanced Studies (International Foundation for Telemetering, 1969-09)
      A series of scientific payloads have been built and flown aboard Nike Apache Rockets. During the design phase heavy emphasis was placed upon realizing a modular configuration both structurally and electrically. The payload was divided into two sections according to functions. The support section included such things as telemetry, batteries, power supplies, timing, aspect sensing and programming facilities. The experiment section was composed of six independent experiments each provided by a different group. Each experiment was built to conform to the shape factor, and electrical requirements of the payload. This paper will discuss the modular nature of the experiments only. The theoretical and instrumental features of the different experimental problems are to be published in other literature along with the research results from the 1969 flight program. The features of the support system which make for maximum modularity will be emphasized in this paper.
    • A New Bandlimited M-ARY Non-Coherent Telemetry System

      Stone, M. S.; TRW Systems Group (International Foundation for Telemetering, 1969-09)
      In this paper new M-ary non-coherent signal structures that require less transmission bandwidth than conventional FSK are presented. A method of synthesizing these signal sets by the use of frequencies or tones is given. In order to evaluate system performance, an approximation to the error probability for large signal energy-to-noise spectral density ratio is derived. Using this formula certain signal structures are evaluated for M = 8, 16, and 32. It is shown that for error rates of less than 1 x 10⁻³, the signal structures that reduce the transmission bandwidth by 25% are within 1 dB of the corresponding FSK signal set. Thus these signal structures provide an efficient method of communication when the bandwidth is constrained to be less than required for the transmission of FSK.
    • An On-Board Processor for OAO-C

      Trevathan, C. E.; Hartenstein, R. G.; Taylord, T. D.; Goddard Space Flight Center, NASA (International Foundation for Telemetering, 1969-09)
      This paper describes the design of a stored program computer for spacecraft use and its application on the fourth Orbiting Astronomical Observatory (OAO-C). The computer, referred to as OBP-2, is a medium scale, parallel machine and has a memory capacity of 16,384 words of 18 bits each. It possesses a comprehensive instruction repertoire and operates on 45 watts of power (including the DC to DC converter). The machine operates at a 667 KHz rate and executes an add instruction in 7.5 microseconds. The primary function of OBP-2 on OAO-C will be auxiliary command storage, spacecraft monitoring and malfunction reporting, data compression and status summary, and possible performance of emergency corrective action for certain anomalous situations.
    • Performance of Partially Coherent Binary Reception

      Okkes, R. W.; European Space Technology Center (International Foundation for Telemetering, 1969-09)
      This paper considers the performance of a partially coherent detector of phase-shift keyed (PSK) modulated binary data, where the receiver's phase reference is noisy and derived from the carrier component of the received signal by means of a narrow band tracking filter (phase locked loop). The statistics of the detector output are derived and the bit error probability is graphically illustrated as a function of the data channel signal to noise ratio, the signal to noise ratio existing in the phase lock loop bandwidth and the phase lock loop bandwidth to bit rate ratio. The results obtained for the single channel partially coherent detector are used to derive the performance of binary data detection after maximum ratio diversity combination of the two video signals, each of them being demodulated by partially coherent detectors.
    • Permutation and Circuland Matrices and the Fast Fourier Transform

      Heenan, N. I.; The Mitre Corporation (International Foundation for Telemetering, 1969-09)
      This paper provides a description of the Fast Fourier Transform and its connection with the circulant and permutation matrices. It is written for the case where the number of discrete time samples is equal to the number of discrete frequency samples but is otherwise not restricted. The paper demonstrates that since the modal matrix of a permutation matrix contains only one bit of information, the evaluation of the discrete Fourier Transform involves considerably fewer than N² multiplications where N is the number of samples involved and is also the order of the matrices involved.
    • A Phase-Locked UHF Telemetry Transponder for Missile Scoring Applications

      Delbauve, J. R.; Naval Avionics Facility (International Foundation for Telemetering, 1969-09)
      The Phase-Locked UHF Telemetry Transponder described in this article is part of the recently conceived Cooperative-Doppler Missile Scoring System. This system obtains the doppler curve of a missile relative to its target, without the use of special scoring equipment in the missile. This is accomplished through comparison of the telemetry information from the missile with a transponded signal from the target aircraft. The transponder is housed in the target aircraft and is responsible for transponding PAM/FM modulation from the telemetry band (2200-2290 MHz) to the scoring band (1760-1850 MHz), while preserving the phase of the modulation during the frequency translation. In order to accomplish this, true phase demodulation of the PAM/FM signal has been achieved through utilization, of the phase-lock technique. Included in this article is an analytical discussion of the phase-lock loop design with derivations of the closed-loop transfer function and response bandwidth; Root-Locus analysis; Bode diagram; and dynamic range and phase response considerations.
    • A Power Combiner for Step Level High Power UHF Solid State Transmitters

      Rose, B. E.; Hughes Aircraft Company (International Foundation for Telemetering, 1969-09)
      A combining network is described which satisfies the requirements of low loss, compact size and input port selection capability. This power combiner, which follows a basic network scheme suggested by E. J. Wilkinson, uses helical wound quarter wave lines for impedance matching, relays for switching inputs in or out, and thick film resistors in the isolation network. The combiner was designed for a UHF solid-state transmitter for a communications satellite. The power level is in excess of 300 watts. From 8 to 16 inputs, from coherently driven power amplifiers, can be selected by command. This step level feature provides a very useful means to achieve maximum utilization of prime power as well as an improvement in reliability through redundancy. Design equations are given for the units. The results of a computer study of losses due to unequal input phases and amplitudes are presented. The equivalent circuit of the network, including parasitics, is described and the compensating elements are discussed. Tests have been made on the completed flight unit, and these results are plotted and discussed.
    • The Realization of Telemetry Transmitters with Very Wide Bandwidths

      Roberts, R. H.; Bertea Corporation (International Foundation for Telemetering, 1969-09)
      The coming of high bit rate PCM and high quality television as common modulation formats has placed stringent bandwidth requirements on telemetry transmitters at S-Band. Two wideband FM transmitters are considered in this report: One for frequency deviations up to ±1 MHz with rates as high as 1.5 MHz; and a new transmitter with up to ±10 MHz deviation and an 8 MHz baseband response. Presented in this report is a new discriminator of the symmetrical Foster-Seeley type. It is capable of 33% peak-to-peak bandwidth and excellent linearity, that allows very wideband requirements to meet in a practical FM feedback transmitter.
    • Recent Developments in Algebraic Decoding

      Chien, R. T.; University of Illinois (International Foundation for Telemetering, 1969-09)
      Recent developments in algebraic coding theory, particularly in the area of decoding techniques, has made the block coding approach much more attractive for practical systems. Advances have been made in decoding algorithms, implementation and software approaches covering such areas as burst correction, random error correction and the correction of multiple bursts. In this paper a review is given on these recent developments from the point of view of applications. These developments shall be discussed with regard to decoding complexity, computational methods, hardware and software considerations, throughput and cost effectiveness tradeoffs.
    • Recent Improvements in the SDP-3 Computer

      Cliff, R. A.; Goddard Space Flight Center (International Foundation for Telemetering, 1969-09)
      The SDP-3 is a small serial computer which will be flown as an engineering experiment on the IMP-I (eye) spacecraft. In this application it will handle data acquisition for four of the scientific experiments. Modifications to the SDP-3 which improve its operation with little change in hardware complexity include: (1) permitting full-word indirect addressing in user mode for all instructions which do not modify the contents of memory, (2) extending output channel capability to cover all of memory, (3) a new subroutine linkage instruction, (4) a conditional skip on memory zero instruction, (5) byte oriented instructions, and (6) improved index register manipulation instructions. The use of 8-bit MSI shift registers produces a significant hardware and power saving at the expense of deleting all left-shifting instructions. Further hardware savings are realized with a special multiplication instruction which allows the MQ register to be deleted. As a result of these, and other, modifications the power dissipation of the SDP-3 has been decreased by 2/3 watt and the number of IC's by 260 while in most respects operation has either been unchanged or improved.
    • RFI Characteristics of a Data Relay Satellite System

      Bryan, John W.; NASA Goddard Space Center (International Foundation for Telemetering, 1969-09)
      The use of geosynchronous satellites for relay of data from near earth orbiting satellites is being considered by NASA. Since these relay satellites will have directional antennas beamed toward the earth at all times any earth based emitter is a potential source of radio frequency interference (RFI). An investigation has been made in an effort to determine the magnitude of this interference. The information presented here is based upon known frequency assignments and known equipment capabilities. All data and analysis presented are for the continental U. S. only and in some respects depicts a bleak picture.
    • S-Band Antenna Systems for Missiles

      Hill, John E.; Grander Associates (International Foundation for Telemetering, 1969-09)
      Some thoughts are presented concerning methods of obtaining reliable RF Telemetry links at S-Band, by sharing the effort to obtain such reliability between the airborne and ground station antennas. The form the specifications for airborne antenna system may take is discussed, as are methods of presenting and evaluating performance data. A brief history of the development of the S-Band antenna system for the Athena H Missile is related. In conclusion a variety of antenna types suitable for missiles are presented with a discussion of their virtues and deficiencies.
    • S-Band Phased Array Telemetry Receiver

      Kent, R. C.; Ryan Aeronautical Company (International Foundation for Telemetering, 1969-09)
      A phased array receiver operating at S-band has been developed to automatically track a moving telemetry transmitter by electronic beam steering. Each array module consists of an antenna, mixer, IF amplifier and local oscillator. Beam steering is accomplished by a unique method of controlling the output phase of the local oscillator. The antenna beam may be moved in a continuous scan through 120° in azimuth and elevation. Tracking rates as high as 100° per millisecond are achieved with no moving parts.