• Miniaturized, Micropower Biomultiplexer Telemetry System Fabricated Utilizing Hybrid Techniques

      Trezek, J. P.; Firstenberg, A.; General Dynamics; University of California (International Foundation for Telemetering, 1971-09)
    • The General Peculiarities of Animal Telemetry

      Cochran, William W.; Illinois Natural History Survey (International Foundation for Telemetering, 1971-09)
    • Appendix A: Tenth Annual Report of the Telemetering Standards Coordination Committee

      Pruss, Hugh (International Foundation for Telemetering, 1971-09)
    • Small Animal Telemetry - An Overview

      Davis, Stanley D.; Case Western Reserve University (International Foundation for Telemetering, 1971-09)
    • Radiotelemetry for Research on Large Land Mammals

      Buechner, H. K.; Smithsonian Institution (International Foundation for Telemetering, 1971-09)
      The use of radiotelemetry for simultaneously monitoring physiological and environmental parameters, while an animal is being tracked in its natural ecosystem, provides new opportunities for increasing our knowledge about the larger land mammals by the acquisition of new information on their migratory movements, social behavior, bioenergetics, and physiological processes such as thermoregulation and water balance. The perfection of satellite tracking and monitoring systems specifically designed for wild animals, such as caribou and elephants, in remote areas of the Earth is feasible; and such systems hold considerable promise in providing access to information that has been exceptionally difficult to obtain in the past. Challenges in the development of practical radiotelemetry systems include: light-weight, long-lasting sources of power; developing systems that require little power; increasing the variety of implantable physiological sensors; improving the resolution of locations (to 100 m or less) for tracking an animal by satellite; improvement of antennas for greater efficiency in transmissions without interfering with the animal's activities; and interfacing implanted sensor-transmitters with long-range transmitters on the animal's surface. The perfection of systems for attachment of instrument packages to polar bears, elephants, and other wild animals is also demanding.
    • High Density Digital Recording with Video Techniques

      Curtis, D.; Rolfe, J.; International Video Corporation (International Foundation for Telemetering, 1971-09)
      A digital recorder which writes or reads digital data at 8 megabits per second and has a storage capacity of 84 billion bits per reel of tape is described. The packing density is in excess of I million bits per square inch on conventional one-inch magnetic tape. The high packing density and transfer rate was achieved through the combination of phase-encoded digital electronics with a helical scan video transport. The use of the helical scan technique permitted extremely efficient utilization of the tape and permitted inclusion of other features, such as high-speed search (400 ips), individually addressable records, and self-threading and cartridge-loading capability.
    • A Laser Link Operating at One Gigabit/Sec

      Boehmer, A. M.; TRW Systems (International Foundation for Telemetering, 1971-09)
      This paper describes the design of a 1 Gbps digital telemetry/ communication system achieving a probability of bit error of 10⁻⁶. The system is based on the use of near future (approximately 2 years) components and is suitable for use in satellite- satellite, ground-satellite, and aircraft-satellite links. Both the advantages and problems associated with the use of laser links are cited, and the techniques used in this system that make use of the advantages and overcome the problems are identified. Small packages and apertures are used to achieve high ERP (116 dBW), narrow beams with small apertures permit use of low prime power (170 watts total for laser), enormously greater link privacy and reduced susceptibility to counter measures is obtained, direct detection eliminates doppler search and tracking, and the small package size gives satellite systems multiple package possibilities. To obtain these advantages very narrow (5 p radian) operational beams must be acquired and tracked, point-ahead offset for relative terminal motions must be implemented, effects of atmospheric disturbances must be minimized if the atmosphere is in the link, and any repeater configurations must demodulate/remodulate because of lack of any laser system capability for frequency translation and amplification. The following unique features of laser systems as opposed to microwave cussed: requirements for acquisition and tracking point-ahead requirements, unique modulation types hand circular polarization, unique types of noise and background shot noise, elimination of doppler direct detection, ability of the receiving system on its receiving aperture, unique atmospheric propagation disturbances, and possibility of signal coding to remove the signal spectrum from the vicinity of the noise spectrum.
    • Projectile High-G Telemetry for Long Range Dynamics Measurements

      Mermagen, William H.; Aberdeen Proving Ground (International Foundation for Telemetering, 1971-09)
      Devices to measure the pitching, yawing, and rolling motion of a projectile from on board and telemeter the measurements to ground receiving stations have been developed. Two of these devices, a solar aspect sensor and an accelerometer, are described in detail. The complete telemetry system with g-hardening to survive gun-launch accelerations is described and techniques for high-g are discussed. The results of several recent flight tests of these yawsondes are presented and show the unique usefulness of the instruments for measuring dynamical behavior of projectiles over their entire flight paths. Hitherto such information has not been available to the shell designer or the aerodynamicist.
    • L-/S-Band Calibration Error Analysis

      Taylor, Ralph E.; NASA (International Foundation for Telemetering, 1971-09)
      A statistical error analysis is performed to determine the degree of uncertainty encountered when calibrating steerable receiving antennas with the solar calibration method. The analysis considers the propagation of precision error indexes. It is shown that a worst-case one-sigma (1σ) uncertainty of ±0.8 dB in system noise temperature occurs for a solar calibration at L-band. Somewhat better precision can be achieved by monitoring the antenna gain-to-noise temperature (G/T) ratio at a station; a worst-case uncertainty of ±0.5 dB (1σ) can be realized. An error analysis is made of a method to determine absolute antenna gain based upon solar flux density. The uncertainty in this type measurement is ±0.7 dB (1σ) at L- and S-band frequencies.
    • VHF/UHF Stellar Calibration Error Analysis

      Taylor, Ralph E.; Stocklin, Frank J. (International Foundation for Telemetering, 1971-09)
      A statistical error analysis is performed to determine the degree of uncertainty encountered when calibrating steerable VHF /UHF receiving antennas with the stellar calibration method. The analysis considers the propagation of precision error indexes. It is shown that an antenna gain calibration by the stellar method has a one-sigma (1σ) uncertainty of ±0.65 dB at 1440 MHz (L-band), and ±0.8 dB (1σ) at 136 MHz (VHF). Somewhat increased precision can be achieved by monitoring the antenna gain-to-noise temperature (G/T) ratio at a station; a worst-case uncertainty of ±0.4 dB (1σ) can be realized at both L-band and VHF. Finally, field test measurements of antenna gain, obtained at 136 MHz in the NASA space tracking and data acquisition network (STADAN), demonstrate an uncertainty of ±1.0 dB, or less, which effectively confirms the analytical result.
    • A Technique for Measuring the Behavior of a Navigational Buoy

      Babb, Lowell V.; Wilmarth, Robert W.; Budridge, Gerald J.; Transportation Systems Center; U.S. Coast Guard (International Foundation for Telemetering, 1971-09)
      A prototype instrumentation package has been designed and fabricated to furnish quantitative information about the stability of an ocean navigational buoy. A total of fourteen electro-mechanical transducers were included in the package to yield attitude, acceleration, and mooring chain tension information about the buoy. By utilizing a six channel telemetry data system and a 4-channel command telemetry system, continuous data from selected sets of transducers were recorded and used to determine the types, sensitivities, and ranges of instrumentation best suited to this application. The number of telemetry channels chosen represents the "best guess" number required in the final program which will consist of five separate instrumentation packages. By integrating the two telemetry systems in the prototype unit, a flexibility of operation was realized that yielded large amounts of useful data at a minimal cost.
    • Measurement and Analysis of Urban Radio Channels for Communication System Design

      Frasco, L. A.; Goldfein, H. D.; U.S. Department of Transportation (International Foundation for Telemetering, 1971-09)
      This paper outlines a program to measure VHF and UHF urban radio channels for playback and analysis in the laboratory. These measurements are required for the design of high data rate communication equipment which makes efficient use of the radio spectrum. We include in this category data communication and surveillance equipment necessary to meet the demands of the variety of command and control functions envisioned for transportation systems by federal, state, and local governments. Included in the paper is a qualitative description of the channel followed by a discussion of the measurement techniques and hardware that will be used. The goal of the measurement program is to develop both analytic and experimental tools for the design and evaluation of advanced communication techniques specialized for signalling over the urban radio channel. These techniques will include modulation waveform design, coding, and the design of receiver structures including those which adapt to measured channel behavior. Future technology will permit complex hardware designs to be used in the implementation of these techniques while maintaining low system cost. The same techniques and approach used here for the urban channel can be applied to other radio channels that occur in transportation systems. In particular, they are applicable to data links for air-ground and high speed ground transportation system uses.
    • High Data Rate Coding for the Space Station Telemetry Links

      Lumb, D. R.; Viterbi, A. J.; NASA; Linkabit Corp. (International Foundation for Telemetering, 1971-09)
      This paper summarizes a study of coding systems for high data rates with potential application to the space station telemetry links. Among the approaches considered were convolutional codes with sequential, Viterbi and cascaded Viterbi decoding. It was concluded that a high-speed (.40 Mbps) sequential decoding system best satisfies the requirements for the assumed growth potential and specified constraints. Trade-off studies leading to this conclusion will be reviewed. Some sequential (Fano) algorithm improvements will be discussed as well as real-time simulation results.
    • Coherent Demodulation of Continuous Phase Binary FSK Signals

      Pelchat, M. G.; Davis, R. C.; Luntz, M. B.; Radiation Incorporated (International Foundation for Telemetering, 1971-09)
      This paper gives achievable bounds for the probability of error of continuous phase binary FSK signals on the white gaussian noise channel. Phase continuity, like convolutional encoding, introduces a dependence between adjacent transmitted signals which can be used to advantage in the demodulation process. It is shown that continuous phase binary FSK can provide a given probability of error with 0.8 db less signal-to-noise ratio than antipodal PSK. The paper also shows how the ideas developed for decoding convolutional codes apply to the demodulation of continuous phase FSK with rational deviation ratio.
    • Microwave Crash Sensor for Automobiles

      Holmstrom, F. R.; Hopkins, J. B.; Newfell, T.; White, E.; U.S. Department of Transportation; Lowell Technological Institute (International Foundation for Telemetering, 1971-09)
      A prototype microwave radar anticipatory crash sensor for automotive applications is described. This system is for prospective use in conjunction with passive occupant restraints--protective devices that require no action on the part of the occupant to insure their effectiveness. Appropriate antenna configuration and circuitry permit position, velocity, and size discrimination of the target in a simple manner. Results of field tests are discussed, including the manner in which system parameters and target characteristics relate to the tradeoff between false alarm rate, miss rate, and system complexity.
    • Frame Synchronization in PCM Telemetry

      Peavey, Bernard; NASA-Goddard Space Flight Center (International Foundation for Telemetering, 1971-09)
      Frame synchronization of PCM telemetry data can be accomplished very effectively by employing the fixed threshold method with a unique strategy. Probability of false sync acquisition and maintenance can be made negligibly small for data having bit error rates less than 10%, at a small sacrifice in acquisition time. Furthermore, experimental results indicate that frame synchronization is significantly affected by the frame sync code length rather than by the code pattern itself, i.e., any pseudo-random code is just as good. The difference in performance between "optimum" codes and any pseudo-random code is negligible.
    • Biomedical Telemetry - A Review and Overview

      Caceres, C. A.; Slater, L. E. (International Foundation for Telemetering, 1971-09)
      Biomedical telemetry has yet to fulfill the high promise generated by its first significant use ten years ago. Most of the progress has been in research biotelemetry; in the monitoring of animal physiology and behavior to gain new insight into both the normal and pathological state. Many clinical applications have developed but few, with the notable exceptions of telephone telemetry systems in cardiology and the monitoring of astronauts, have achieved wide acceptance. The nub of the problem has been the bias in equipment design and system orientation towards research criteria. There is a compelling need and opportunity for telemetric systems specifically designed for clinical, or on-the-spot, use.
    • On the Timing Problem in Optical PPM Communications

      Gagliardi, R. M.; University of Southern California (International Foundation for Telemetering, 1971-09)
      The use of digital transmission with narrow light pulses appears attractive for data communications, but carries with it a stringent requirement on system bit timing. In this paper we investigate the effects of imperfect timing in a direct detection (noncoherent) optical system using PPM bits. Particular emphasis is placed on specification of timing accuracy, and an examination of system degradation when this accuracy is not attained. Bit error probabilities are shown as a function of timing errors, from which average error probabilities can be computed for specific synchronization methods. Of significant importance is the presence of a residual, or irreducible error probability, due entirely to the timing system, that cannot be overcome by the data channel.
    • Clinical Biotelemetry

      Kilpatrick, David G.; Kilpatrick Associates, Inc. (International Foundation for Telemetering, 1971-09)
      Telemetry and telemetric techniques are of increasing significance in clinical medicine. Diagnostic data is acquired in this way for both manual and automated interpretation or processing. It has become practical to assemble clinical monitoring systems from non-custom equipment. Clinical biotelemetry is reviewed briefly, and a recent composite system is described in some detail.
    • A Real Time Programmable Data Compression System for Video Data

      Kutz, R. L.; Davisson, L. D.; NASA Goddard Spaceflight Center; University of Southern California (International Foundation for Telemetering, 1971-09)
      This paper describes the implementation of a data compression system for the real time operational transmission of advanced technology satellite (ATS) pictures between the command and data acquisition (CDA) station located at Wallops Island, Virginia and the National Environmental Satellite Service (NESS) at Suitland, Maryland over broadband microwave links. The system features the use of general purpose minicomputers for encoding and decoding which makes it possible to easily vary the data compression technique in use and to make simultaneous statistical calculations on the data. Special interfaces to the pre-existing equipment have been designed to insure efficient use of the parallel structure of the computers. Data compression and expansion is done in a way that results in no lowering of data quality.