• International Telemetering Conference Proceedings, Volume 24 (1988)

      International Foundation for Telemetering, 1988-10
    • Telemetry Chart Recording Via Direct Digital Link

      Smith, Grant M.; Alexander, James H.; Astro-Med, Inc. (International Foundation for Telemetering, 1988-10)
      Mission safety and cost-efficiency concerns have resulted in a resurgence of interest in real-time strip chart recorders. But conventional recorder technologies require inordinate maintenance and daily calibration. Attempts at strip chart emulation involving costly dedicated microcomputers and CRT's have failed, because the chart itself is not real-time, a basic requirement. The concept of an inexpensive, direct digital link to a telemetry processing computer (VAX, e.g.) is discussed. A thorough examination of real-time monitoring of critical, non-repeatable data is presented. Objectives: An automated, turn-key telemetry data system. Reduce the routine maintenance required by conventional recording systems; eliminate the need for digital-to-analog converters (DAC's); and improve the efficiency of range personnel and the integrity of recorded data.
    • A New S-Band FM Telemetry Transmitter

      Fengden, Lou; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1988-10)
      This paper describes the design, test and the analysis of the test results of a new type S-band FM telemetry transmitter. Compared with the modulator adopting conventional fundamental crystal direct modulation, the transmitter which adopts UHF fundamental crystal direct modulation has a comparatively better modulation characteristics and a higher center frequency stability. The test results show that the deviation sensitivity of the transmitter is up to 400KHz/Vrms, frequency response is DC~200 KHz, total harmonic distortion is 3% and the center frequency stability is ten to the minus fifth power within the range of - 30~+70°c. Because of the high operating frequency of the modulator, the complicacy of the frequency multiplier has been requced, design of circuitry simplified and harmonic and spurious outputs has been improved to a great extent.
    • Utilization of Real Time Digital Strip Chart Emulation (RTDSCE) Concepts

      Halsey, Tim; Brimbal, Michel; Grottenthaler, Gary; Gould Incorporated (International Foundation for Telemetering, 1988-10)
      "Real Time Digital Strip Chart Emulation", a paper presented in the 1987 ITC Proceedings is reviewed for continuity and the digital techniques applicable to range data display are expanded upon. The paper seeks to present the process of recording telemetered signals in the RTDSCE data management scheme. Direct hardware interfacing is discussed with emphasis on automation and manpower reduction. Time code display and various mass storage possibilities are explored. The merits of video monitoring and the workstation concept during playback are evaluated.
    • Research and Recommendation of Optimum Group Synchronization Codes for N = 7 -- 32

      Zhongkui, Lei; Qiucheng, Xie; Jie, Cao; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      In this paper, based on a series of research achievements [2,3,4,5,6], are examined the "The Optimum Frame Synchronization Codes" provided by J. L. Maury Jr. and F. J. Styles for IRIG Telemetry Standards USA, and furthermore, recommended a set of Optimum Group Synchronization Codes for China Telemetry Standards.
    • A New Microcomputer-Based Reel Servo System in the Instrumentation Magnetic Recorder

      Rui, Xiong; Yunxiang, Shao; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1988-10)
      This paper describes the design of a adaptive microcomputer-based reel servo system in the instrumentation magnetic recorder. When the reel parameters and load characteristics might vary during recording, the newly designed adaptive reel servo system is capable of compensating for these variations. The new reel servo system consists of a single-board microcomputer (QJ-80) and two D.C. motor actuators. A model reference adaptive control was chosen as the basis for adaptive reel controller design. The experiment results show that the new microcomputer-based reel servo system effectively eliminates the affect of the parameter variations. The performance of the whole transport system is improved therely.
    • Telemetry Data Processing: A Modular, Expandable Approach

      Devlin, Steve; Aydin Monitor Systems (International Foundation for Telemetering, 1988-10)
      The growing complexity of missle, aircraft, and space vehicle systems, along with the advent of fly-by-wire and ultra-high performance unstable airframe technology has created an exploding demand for real time processing power. Recent VLSI developements have allowed addressing these needs in the design of a multi-processor subsystem supplying 10 MIPS and 5 MFLOPS per processor. To provide up to 70 MIPS a Digital Signal Processing subsystem may be configured with up to 7 Processors. Multiple subsystems may be employed in a data processing system to give the user virtually unlimited processing power. Within the DSP module, communication between cards is over a high speed, arbitrated Private Data bus. This prevents the saturation of the system bus with intermediate results, and allows a multiple processor configuration to make full use of each processor. Design goals for a single processor included executing number system conversions, data compression algorithms and 1st order polynomials in under 2 microseconds, and 5th order polynomials in under 4 microseconds. The processor design meets or exceeds all of these goals. Recently upgraded VLSI is available, and makes possible a performance enhancement to 11 MIPS and 9 MFLOPS per processor with reduced power consumption. Design tradeoffs and example applications are presented.
    • VLSI High Speed Packet Processor

      Grebowsky, Gerald J.; Dominy, Carol T.; NASA Goddard Space Flight Center (International Foundation for Telemetering, 1988-10)
      The Goddard Space Flight Center Mission Operations and Data Systems Directorate has developed a Packet Processor card utilizing semi-custom very large scale integration (VLSI) devices, microprocessors, and programmable gate arrays to support the implementation of multi-channel telemetry data capture systems. This card will receive synchronized error corrected telemetry transfer frames and output annotated application packets derived from this data. An adaptable format capability is provided by the programmability of three microprocessors while the throughput capability of the Packet Processor is achieved by a data pipeline consisting of two separate RAM systems controlled by specially designed semi-custom VLSI logic.
    • Reliable Solid State Data Storage Device for Spacecraft T&C Subsystems

      Capots, L.; Chitty, R.; Ameti, A.; Mitchell, W.; Fairchild Space Company (International Foundation for Telemetering, 1988-10)
      Fairchild Space Company, a division of Fairchild Industries, has developed an advanced data recorder based exclusively on the use of Solid State circuitry for the recorder memory. This paper describes the recorder, its development, the engineering considerations for long-term mission life, methods for minimizing size, weight and power, and the flexibility of the recorder to accommodate a number of different mission requirements. Unlike the more traditional mass storage devices for spacecraft, which use rotating memory, the Solid State Recorder (SSR) uses a true random access memory. This feature has resulted in a multi-mode storage device, which can greatly reduce the complexity of spacecraft data systems. Today's spacecraft have large numbers of sensors and high rate instruments which are making the data flow problem much more difficult to handle. Bottle necks also referred to as "data fusion" have become a serious problem for systems engineers, for which the SSR may represent an effective solution. The paper concludes with a discussion of some system applications which illustrate the broad range of possible SSR applications, and the development status.
    • Fiber-Optic Local Area Network for Real-Time Telemetry

      Bartley, Tom; Loral Instrumentation (International Foundation for Telemetering, 1988-10)
      For years, standard telemetry decommutators have proven the practical effectiveness and other advantages of using a data-driven (or data flow) broadcast bus for collecting, merging, and distributing continuous flow, real-time data. Bus length constraints have limited the use of the wideband broadcast bus to within a single chassis or closely mounted multiple chassis. Standard fiber-optic interfaces now make it possible to extend a real-time, greater than 5 million word/sec tag and data broadcast bus over kilometers at costs comparable to computer local area networks (LANs). Other advantages of this type of LAN include: no software protocol or handshaking, great flexibility in widely distributed processing and data base management, data security, and readily available off-the-shelf products. This paper discusses design considerations for conceptual networks, shows a sample design based on standard products, and suggests opportunities for product development for various types of network nodes. Also discussed are the implications to distributed processing and merging of real-time continuous data streams into the more blocked environment of general purpose computer processing and data base management.
    • Characteristics and Uses of Multipoint Radio in the 950 MHz Telemetry Band

      Ziemienski, Bruce V.; City of Fresno, California (International Foundation for Telemetering, 1988-10)
      Data communications is one of the fastest growing industries today. Many see data communications as one key to increasing workforce productivity. Communications circuits are becoming increasingly expensive especially if wireline is used. A simple solution to this problem is utilized radio. With the advent of the new Multi- Point distribution Service on the 950 MHz Microwave band, simple and relatively inexpensive solutions to data communications distribution has been solved. This paper will explore this new service and its uses as related to data communications.
    • Ruggedized Television Compression Equipment for Test Range Systems

      Gattis, Sherri L.; Naval Weapons Center (International Foundation for Telemetering, 1988-10)
      The Wideband Data Protection Program was necessitated from the need to develop digitized, compressed video to enable encryption.
    • High Performance, Real-Time, Parallel Processing Telemetry System

      Powell, Richard L.; Williamson, Gale L.; Razavian, Farhand; Friedman, Paul J.; Loral Instrumentation (International Foundation for Telemetering, 1988-10)
      Flight test and signal and image processing systems have shown an increasingly voracious appetite for computer resources. Previous solutions employed special-purpose, bit-sliced technology to supplant costly general purpose computers. Although the hardware is less expensive and the throughput greater, the expense to develop or modify applications is very high. Recent parallel processor technology has increased capabilities, but the high applications development cost remains. Input/output (I/O) such as intermediate mass storage and display has been limited to transfer to general purpose or attached I/O computers. The PRO 550 Processing and Storage Subsystem of the System 500 was developed to provide linearly expandable, programmable real-time processing and an interface to distributed data acquisition subsystems. Each data acquisition subsystem can acquire data from multiple telemetry and other real-time sources. Processing resources are provided by one or more 8 MIPS (20 MFLOPS peak) processor modules, which utilize an array of predefined algorithms, algorithms specified by algebraic notation, or developed via high level languages (C and Fortran). Setup and program development occur on an external, general purpose color graphics workstation that is connected to the subsystem via an Ethernet network for command, control, and resultant data display. High-performance peripherals and processors communicate with each other via a 16-MHz broadcast bus, the MUXbus II, where any or all devices can acquire data elements called tokens. A token is a single MUXbus II word of 32 bits of data and a 16-bit tag to identify the word uniquely to the acquiring modules. The output of each device to the bus can be one or more tokens, but each device captures the bus to insert a single token. This ensures all devices receive equal priority and the MUXbus II is maximally utilized. This multiple instruction, multiple data (MIMD) architecture automatically schedules and routes data to processors or to I/O modules without control processor overhead. Traditional peripherals and administrative functions utilize the second subsystem bus, which is a traditional VMEbus. It controls the high performance devices while permitting the utilization of standard off-the-shelf controllers (e.g., magnetic tape, Ethernet, and bus controllers) for less demanding I/O tasks. A dedicated Bridge Module is the gateway for moving data between bus domains.
    • Static RAM Data Recorder for Flight Tests

      Stoner, D. C.; Eklund, T. F. F.; Sandia National Laboratories (International Foundation for Telemetering, 1988-10)
      A static Random Access Memory (RAM) data recorder has been developed to recover strain and acceleration data during development tests of high-speed earth penetrating vehicles. Bi-level inputs are also available for continuity measurements. An iteration of this system was modified for use on water entry evaluations.
    • 19mm Rotary Digital Data and Instrumentation Recording

      DeFrancesco, Richard E.; Honeywell (International Foundation for Telemetering, 1988-10)
      A new family of recording devices has emerged which are user-friendly, 19mm cartridgebased use a MIL-STD format, and are capable of high transfer rates for diverse applications.
    • System Aspects of Digital Video Telemetry

      Deutermann, Alan R.; Randall, Neil C.; Delta Information Systems, Inc. (International Foundation for Telemetering, 1988-10)
      This paper describes a completely integrated digital video telemetry system and analyzes several critical aspects of that system. The typical video network may consist of video source signals on the ground as well as airborne while the receive site is usually ground based. Examples of system issues which will be described and analyzed are listed below. * Multi-mode operation: It is likely that a single receive site must be able to rapidly switch between video sources having different bit rates and modes of operation. One technique to achieve this capability will be presented and discussed. * Error sensitivity: It is important that the coding compression technique be resilient to transmission errors. Techniques to achieve this robustness for both synchronization and data signals will be discussed. * Data Multiplexing: From a system point of view, it is extremely efficient to multiplex other digital signals (e.g. audio, IRIG time code) with the video signal to form a single stream for encryption and transmission. A particularly efficient multiplex technique will be presented. * Diagnostics: Video telemetry systems are more effective when they contain carefully designed built-in diagnostics. Advanced concepts for both board-level and system-level diagnostics will be presented.
    • Spacecraft Telemetry Tracking State of the Art and Trends

      Mayer, Gerhard; DFVLR Applied Data Syst. Div. (International Foundation for Telemetering, 1988-10)
      Telemetry Tracking is a method of obtaining trajectory information regarding any flying body such as an aircraft, missile, satellite, balloon or a deep space probe which signals or "marks" its flight position by an electromagnetic radiating source. In a trade-off of costs it is an attractive way to combine Telemetry, Tracking and Command (TTC) facilities into one integrated system on board a spacecraft and with the ground receiving and tracking facilities. The present state of the art of Distance Measuring Equipment (DME) and Angle Measuring Equipment (AME) integrated with telemetry systems is reviewed. The further development will be mainly stimulated by the technology evolution of frequency and time reference sources, microwave components and information processing systems. An attempt is made to analyse which way the growth of technology will influence various system parameters.
    • Modem Simulations for Possible Use in Space Station

      Horan, Stephen; New Mexico State University (International Foundation for Telemetering, 1988-10)
      Two candidate modem structures for use in the Space Station Multiple Access Communications System were simulated using a software simulation package to obtain symbol error rate curves. These systems represent an evolutionary QPSK through 8-PSK modulation format for the input data streams. It was found through the simulations that the use of phase-staggered QPSK modems would give lower expected implementation loss than a modem based upon the Polarity Costas Loop method. However, the latter would represent a simpler hardware investment to realize the modem structure for both QPSK and 8-PSK.
    • Video Compression Techniques

      Cilke, Tom; LORAL/CONIC (International Foundation for Telemetering, 1988-10)
      This paper will attempt to present algorithms commonly used for video compression, and their effectiveness in aerospace applications where size, weight, and power are of prime importance. These techniques will include samples of one-, two-, and three-dimensional algorithms. Implementation of these algorithms into usable hardware is also explored but limited to monochrome video only.
    • A Charge-Balancing Incremental Analog to Digital Converter for Instrumental Applications

      Zrilić, D.; Skendzić, D.; Pajavić, S.; Ghorishi, R.; Fu, F.; Kandus, G.; Boston University (International Foundation for Telemetering, 1988-10)
      A switched-capacitor technique for realization of one bit serial A/D converter is presented. A conversion accuracy that is higher than 15 bits can be expected from its integrated realization. Results of simulation are presented. It is shown that arithmetic operations on bit serial signals are possible. Using arithmetic operations on delta-modulated signals, it is possible to build inexpensive options necessary in instrumentation.