• Simple Digital Encoder for NTSC Composite Video

      Milles, George T.; Naval Weapons Center (International Foundation for Telemetering, 1988-10)
      The need exists to encode NTSC composite video into a serial digital bit stream for encryption prior to transmission. Further, this need exists in places where power and volume are at a premium. This paper describes a simple solution using the Continuously Variable Slope Delta Modulation technique of encoding all lines and fields in real time and is usable with clock rates from 5 to 25 MHz. The circuits presented use only a 5-volt power supply and two active devices: a comparator and either a dual flip-flop or serial shift register.
    • 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.
    • 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.
    • 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.
    • 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.
    • Analysis On the Optimum Group Synchronization Code of TIROS Satellite

      Qiu-Cheng, Xie; Jie, Cao; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      In this paper, the group synchronization code (length n = 60 bit) of the TIROS Satellite was analysed. It seems to us the code isn't optimization. A series of optimum group sync codes (n = 60) have been searched out with error tolerance E = 1, 2, 3, 4, 5, 6 and 10, 12. Their error sync probabilities are less than the error sync probability of the TIROS code (from two times to two order of magnitudes about). These optimum or qansi-optimum codes will be presented for application in the second generation of the Meteorological Satellites of China.
    • Trends in Telemetry Systems

      Strock, O. J. (Jud); Fairchild Weston Systems, Inc. (International Foundation for Telemetering, 1988-10)
      This tutorial is an examination of trends in telemetry systems as we approach the 1990s. . . a look at where we are, and where we appear to be headed in the near future. Historically, the typical change in our technology is brought about by one of three conditions. First, users demand performance improvements in order to facilitate their analysis of test programs. Second, manufacturers make performance improvements because continuing advances in component technology enable them to offer improved products for telemetry applications. Third, developments in non-telemetry applications, both hardware and software, are adapted to our needs by system designers. We will see the results of all three conditions as we look at trends in telemetry systems.
    • Characterization of Self-Focusing and Self-Defocusing of Light in Sodium Vapor

      Largent, C.; Northwestern University (International Foundation for Telemetering, 1988-10)
      Self-focusing of light in sodium vapor was first observed on a cw basis in 1974. Recently at Northwestern University, efforts to develop a quantum optical communications network employing squeezed states of light have required quantitative characterization of the self-action effects. It has been determined that self-focusing and self-defocusing change the spatial structure of the output beams of the forward four-wave mixer used in the experiments, thus worsening the homodyne-detection efficiency by creating a mismatch between the squeezed output beam and the local-oscillator beam. Consequently, the need to characterize the self-action effects in sodium vapor has arisen. By characterizing the self-action effects as a function of the sodium cell temperature, input beam intensity, and the dye laser frequency, it will be possible to modify the localoscillator wavefront to compensate for the spatial mismatch, and thus improve the homodyne-detection efficiency. This paper reports the results of an experiment carried out in the Fall and Winter Quarters of the 1987/1988 school year as an Honors Project in Electrical Engineering. The theories of self-focusing of optical beams and Gaussian beam propagation are developed early in the paper in order to lay the groundwork for the presentation and interpretation of the experimental results. A general description of the laboratory setup is given, and the experimental procedure is described in detail. Finally, the paper concludes with a presentation and interpretation of the experimental findings.
    • The IPTN's Airborne Data Relay System (ADReS): A System Concept and the Phase One System Configuration

      Soelaiman, Adi Dharma; Roesma, Fauzi Effendy; Indonesian Aircraft Industry Ltd. (International Foundation for Telemetering, 1988-10)
      By making use of NC212-200 commuter aircraft as an airborne container, the ADReS, a short for airborne data relay system, had been configured and tested in an experimental status during the year of 1987. A kind of test on EMC, EMI, RFI and telemetry data link were applied to the system. Prior to the IPTN's flight test program in the year of 1988 - 1992, the ADReS is designed not only to receive and to relay the data, but also planed to be able to process the data for quick data analysis purposes on board. This paper describes the ADReS system concept and its experimental status system - the Phase One system configuration.
    • A PCM Telemetry System Using Programmable Logic Devices

      Stewart, Michael T.; Sandia National Laboratories (International Foundation for Telemetering, 1988-10)
      This paper discusses a PCM telemetry system consisting of programmable logic devices (PLDs) and off-the-shelf analog ICs. A finite state machine (FSM) serves as the system controller. All digital logic, including the FSM, is implemented using PLDs. This approach has two important features. First, the use of an FSM offers a significant speed advantage over microprocessor-controlled systems. Second, the use of PLDs offers a high degree of design flexibility while obtaining a low-power, low-volume system.
    • Performance of Contention Bus Networks with Baseband Captures

      Ward, Dale; Northwestern University (International Foundation for Telemetering, 1988-10)
      Power capture is the characteristic of one signal overpowering the others in contention for a receiver. In a multiple access network which employs contention protocol, occurrence of capture helps a receiver distinguish correctly one signal given that multiple transmissions overlap over the common channel. It has been reported in the literature that performance of radio networks could substantially be higher in the presence of captures than it is without captures. The captures involved in radio networks are primarily FM captures. In this paper, we examine the effect of baseband captures on performance of contention bus networks. In particular, we show that signal attenuations on a cable channel could produce a significant chance of captures and hence greatly lift the throughput.
    • Generic Telemetry Processing: Theory vs. Application

      Pettit, Richard L., Jr.; Telos, Inc.; Jet Propulsion Laboratory/California Institute of Technology (International Foundation for Telemetering, 1988-10)
      The Space Flight Operations Center (SFOC) is a generic suite of ground data systems software. One main subsystem of SFOC is the Telemetry Input Subsystem (TIS). Utilizing techniques for the abstract representation of data, the TIS has provided a flexible software base that can be used as a baseline for multiple spacecraft missions.
    • Generic Decommutation Capabilities in the Space Flight Operations Center

      O'Brien, Robin A.; Jet Propulsion Laboratory/California Institute of Technology (International Foundation for Telemetering, 1988-10)
      A generic decommutation capability has been created as part of the Space Flight Operation Center's goal of developing a multi-mission telemetry system. Generic decommutation involves separating the algorithmic description for extracting data from the actual implementation of decommutation. This was done by creating a Decommutation Map Language, which allows mission designers to describe decommutation algorithms without the restrictions imposed by a standard programming language. A Decommutation Map Compiler converts this description into C code, which is then linked with a decommutation library to provide an executable decommutation program. So far, this approach has been used successfully to decommutate several different types of data.
    • Data System Overview

      Karhr, Joseph R.; Jet Propulsion Laboratory/California Institute of Technology (International Foundation for Telemetering, 1988-10)
      The design of the SFOC data system is based on a "design for change" philosophy. It emphasizes standards throughout the implementation, allowing for reuse of software, for periodic changeout of hardware, and for an evolving network configuration. Commercial off-the-shelf hardware and software components are incorporated in a way that avoids dependencies on any single vendor. Multiple flight projects are supported by building upon the baseline system with a minimum of special purpose adaptations. In addition to the multi-mission aspect of SFOC, it must also satisfy multiple users representing multiple disciplines. Data system operators monitor and control SFOC itself. Spacecraft team members keep a vigil to protect the health of the spacecraft. Mission planners and sequence designers control the spacecraft. Science investigators remotely calibrate and control their onboard instruments. SFOC provides near-realtime and nonrealtime support to end-users for downlink (telemetry) and uplink (command) functions. This paper provides an overview to the design of the overall SFOC system and describes the implementation of the current baseline SFOC. It summarizes the important design decisions that have been made, and explains the approach taken to meeting these challenging requirements.
    • Several Problems in Chinese Development of Telemetry Technology

      Chang-jie, Shi; Shang-ren, Li; Ministry of Aeronautics and Astronautics; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1988-10)
      1. What is the reason for the telemetry ground station using computer technology widely and deeply? 2. How to solve the problem of measuring fast varing signal? 3. Bit rate of telemetry ground station.
    • Software Control of a High Speed, Modular Signal Conditioner and PCM Encoder System

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1988-10)
      The increasing channel capacity and complexity of flight test data acquisition systems have made the problems of physical distribution of the system throughout the test aircraft and determining the system configuration a very time consuming and costly portion of the flight test process. These problems are complicated because the new aircraft, irrespective of size, have more complex systems and less space is available to install the classical data acquisition and recording system. The solution to the installation problem is to have a highly modular system that can be configured as either a distributed system with remote multiplexing and a PCM Central Controller, or with the same multiplexed hardware as a stand-alone or master/slave system where the functional power and complexity afforded by the PCM Central Controller are not required. The solution to the configuration control problem is to have a 'hands-off' data acquisition system with all variables of the signal conditioning and PCM encoding functions under software control. In one concept, this includes functions such as instrumentation amplifier gains and offsets, presample filter knee selection, a common gain programmable amplifier with programmable offsets, and randomly addressable multiplexers with a PCM Central Controller that can store multiple data cycle maps. With all of the variable functions of the system under software control, system configuration can be determined automatically during pre- and post-flight test from a portable ground test set that produces a hardcopy printout of the system configuration. This system concept is being augmented by increasing sampling rate capability up to 500k sps for processing vibration/acoustic data. Fiber optical communications are available between the PCM Central Controller and the remote signal conditioners and multiplexers to provide immunity from extremely high common mode plateaus between subsystem elements located in different parts of a composite materials airframe. This next generation data system is being developed for general purpose flight and ground test applications.
    • MMTS: Multi-Vehicle Metric & Telemetry System

      Aspnes, Richard K.; Yuma, Russell J.; Control Data Corporation (International Foundation for Telemetering, 1988-10)
      The Multi-Vehicle Metric & Telemetry System (MMTS) is a complete range system which performs real-time tracking, command destruct, and telemetry processing functions for support of range safety and the test and evaluation of airborne vehicles. As currently configured, the MMTS consists of five hardware and software subsystems with the capability to receive, process, and display tracking data from up to ten range sensors and telemetry data from two instrumented vehicles. During a range operation, the MMTS is employed to collect, process, and display tracking and telemetry data. The instrumentation sites designated for operational support acquire tracking and telemetered data and transmit these data to the MMTS. The raw data is then identified, formatted, time tagged, recorded, processed, and routed for display to mission control and telemetry display areas. Additionally, processed tracking data is transmitted back to instrumentation sites as an aid to acquire or maintain vehicle track. The mission control area consists of a control and status console, high resolution color graphics stations, and large screen displays. As the mission controller observes mission progress on the graphics stations operational decisions can be made and invoked by activation of the appropriate console controls. Visual alarms provided my MMTS will alert mission control personnel of hazardous conditions posed by any tracked vehicle. Manual action can then be taken to activate transmission of the MMTS vehicle destruct signal. The telemetry display area consists of ten fully-functional, PC compatible computers which are switchable to either of two telemetry front end processors. Each PC can be independently set up by telemetry analysts to display data of interest. A total of thirty data pages per PC can be defined and any defined data page can be activated during a mission. A unique feature of the MMTS is that telemetry data can be combined with tracking data for use by the range safety functions.
    • A Flexible Telemetry Processor for Spacecraft Testing

      Leng, Christopher; Peet, Arthur; Jet Propulsion Laboratory/California Institute of Technology; Martin Marietta Astronautics Group (International Foundation for Telemetering, 1988-10)
      In the past, telemetry data systems in support of JPL flight projects -- such as Voyager and Galileo -- were designed specifically for each mission. Third-generation computers and minicomputers were combined into a distributed system, and many man-hours of software development were invested to meet each project's unique processing requirements. These systems were used to support the Spacecraft testing on the ground and -- later -- for mission operations after launch. The Magellan System Test Data Processing Subsystem (STDPS) marks a departure from these past designs. For the first time, a re-usable telemetry-processing subsystem has been designed that is flexible enough to meet the spacecraft-testing requirements of the present project -- and can be easily changed for future projects as well. These changes are all accomplished through a user-friendly, menu-oriented interface. Extensive software re-programming is no longer required. The Magellan spacecraft is being constructed for JPL by Martin Marietta Astronautics Group, Denver, Colorado. The STDPS is currently in Denver, supporting the spacecraft testing.