• Designing and Reliability Assessment to Fault-Tolerant Telemetry Systems

      Ji-San, Lu; Beijing Institute of Special Mechanical and Electrical Devices (International Foundation for Telemetering, 1988-10)
      In the areas of space technique, It is required that telemetering systems have higher reliability then the observied monitor systems. However, the reliability of telemetering systems themselves are generally lower then that of required. For this reason, this paper discusses the necessity of designing Fault-Tolerent Telemetering Systems, and the main methods to improve the reliability of Non-Fault-Tolerant Telemetering Systems. This paper also discusses the objective, principle, methods to designing Fault-Tolerant Systems, and presented the analysis results of reliability assessment
    • Digital Color TV Telemetry

      Schaphorst, Richard A.; Comeau, Charles P.; Delta Information Systems, Inc. (International Foundation for Telemetering, 1988-10)
      In most of the initial applications of digital TV telemetry the video source signal is monochrome (typically RS-170 standard). However color TV is now employed extensively in many of the government test ranges, and it is likely that it will be required to digitally transmit the NTSC color TV signal for security and other reasons. It is also likely that the bit rates which will be employed for this transmission will range from 1 to 20 mbps depending upon the application. This paper presents the general issues involved in digitizing color TV signals, describes alternative color coding techniques, compares these alternatives, and describes one particularly promising approach in detail. Alternative coding techniques that will be discussed and analyzed include direct coding of the composite NTSC signal as well as several component coding concepts - Y, I, Q; Y, R-Y, B-Y; and the transmission of chroma lines on an alternating basis. Specific techniques for multiplexing the digitized color component signals will be presented. It is desirable that the color coding technique be an incremental expansion relative to existing monochrome coding concepts. One particular technique which shows promise of meeting this objective is presented and discussed.
    • Digital Microwave System Mobile, All-Terrain System for Telemetry or Communications

      Strom, Robert L.; Emmenegger, J. M. (Hans); Boeing Aerospace Company; Broadcast Microwave Services, Inc. (International Foundation for Telemetering, 1988-10)
      Portable, mobile tactical microwave telemetry and/or communications systems have always been plagued with three major problems: antenna height for first fresnel zone clearance over the terrain between the two ends of the link, atmospheric multipath fading and multipath reflections from buildings, bodies of water, certain terrain features, etc. This paper describes a digital microwave system with a modular capability to add additional digital channels, analog channels or voice channels as required. A modular Baseband Processor is used, which provides multiplexing capability and modulation of high speed digital data at a bandwidth of one bit per Hz using the Duobinary Technique which also provides error detection capability without the need for adding extra bits to the stream.
    • A Digital Video Link for Telemetry Applications

      Ottesen, Cory W.; Sandia National Laboratories (International Foundation for Telemetering, 1988-10)
      Using a simple, yet flexible, pixel compressor and a frame buffer, a compact digital video link has been built which allows a trade-off between bit rate, spatial resolution, and frame rate.
    • Distributed, Real-Time, High-Resolution Color Graphics Display System for Telemetry

      Querido, Robert; Friedman, Paul J.; Loral Instrumentation (International Foundation for Telemetering, 1988-10)
      Dramatic increases in telemetry data rates and sources require test engineers to view and digest real-time data in order to make cogent decisions about whether to continue or modify flight tests. Traditional telemetry systems offer limited insight through a myriad of strip charts and alphanumeric displays. Attempts to improve this human interface employed expensive central superminicomputers and display systems. Although these methods have been successful, development and procurement costs and delays have limited their deployment. Recent advances in low-cost standard display, processing, and network technology have led to the development of the System 500. The System 500 employs a distributed architecture. Independent, relatively low cost, high-resolution color graphics workstations connect to the data acquisition and processing subsystems via Ethernet.* Each station is independent, requesting and then receiving only data for display. The combined ability to physically display and update only a few hundred parameters, each at relatively few samples per second makes Ethernet and standard upper layer protocols ideal for this application. The state-of-the-art human interface lets users select or mix a variety of methods to create and modify display contents, including: choosing from a list using arrow keys or a mouse, moving a scroll bar to pan through parameter files, or entering commands via keyboard where response anticipation reduces keystrokes to those uniquely defining a choice. A repertoire of graphic window displays is available to present real-time and static data concisely in analog and alphanumeric formats. Window size, location, and color have been chosen to focus attention rather than beautify. Standard windows and accent colors direct user attention to specific areas without cluttering and distracting.
    • A DPCM Approach to Video Compression

      West, Jim; Moore, Willard; LORAL/CONIC (International Foundation for Telemetering, 1988-10)
      This paper presents a working Variable Length Differential Pulse Code Modulation (VDLPCM) video compression/decompression and encryption system. Included are theory of operation and performance characteristics, as well as a study of packaging problems which arise from using this hardware for severe environmental applications. No classified issues are covered.
    • Draft Standard for Digital Transmission of Television Images

      Rieger, James L.; Gattis, Sherri; Naval Weapons Center (International Foundation for Telemetering, 1988-10)
      This paper describes the characteristics of the HORACE digital protocol intended for transmission of black-and-white standard television images and associated data through a digital channel and reconstruction of an NTSC standard television picture at the receiving end, using adaptive transmission to allow maximum picture quality at a selected data rate. Tradeoffs are discussed for transmission rates in the range from near DC to over 40 Mbits/second. The HORACE protocol will be a government test range standard to be issued by the Telecommunications Group [TCG] of the Range Commanders' Council as RCC Document 209.
    • Evolutionary Factors in the Development of a Realtime Multiprocessor System

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1988-10)
      Architectural decisions made three years ago in the design of a high speed preprocessor system for realtime data processing at sustained rates of 200k to 300k parameters per second were driven by the need to provide expansion flexibility and to permit the user to program application algorithms through the use of a high level language. The original design concept was a two bus architecture which would accept and merge data from up to 8 data sources with the required number of parallel computers driven by the realtime processing needs - not the 1.5M wps aggregate throughput capability. Other configuration variables were to enable the use of an optional raw data circular (wrap around) file for intermaneuver or anomaly analysis, the number of analog and discrete outputs for strip chart and visual displays, and the ability to support a wide range of processed data throughputs to one or more host computers. As a result of future defined requirements, the expansion capability ultimately grew to allow up to 30 data sources, 256 analog outputs, and 196 discrete outputs. A concurrent study of the engine and airborne test community showed that in many applications over 50% of the processing was restricted to repetitive computations such as FFTs and first order EU conversions. Although bit slice processors were much faster than general purpose Application Processors (APs), nobody in the user community said they wanted to write microcode to install their application programs. As the first customer's requirements could be easily handled by adding a few APs, the initial system design concentrated only on general purpose processors with provisions being made for the future addition of special purpose digital signal processors to co-reside with the general purpose APs. At the some time, much of the rotary wing test community's data processing was highly floating point intensive so the AP processor was designed with an independent floating point processor using the fastest possible device technology. The original two bus architecture using industry standard Versa and VME buses evolved as the design matured to a six bus architecture capable of supporting up to 60 parallel processors. The use of industry standard buses has permitted successful development of configurations using a wide range of third party processors and peripherals from a variety of sources. Larger system configurations are implemented by a multi-chassis structure with functions arranged so that no realtime bus is unterminated or physically longer than 19 inches. The simultaneous software development supporting these changes and encompassing 25 man-years of work is beyond the scope of this paper and will be covered in a separate publication.
    • 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.
    • 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.
    • Flight Test of SDM Telemetry System

      Ming, Zheng; Qi-shan, Zhang; Beijing Institute Aeronautics and Astronautics (International Foundation for Telemetering, 1988-10)
      Orthogonal functions are the mathematical foundations of implementing multiplex transmission. Walsh functions are a set of functions which are orthogonal, normalized, and complete. They can also be used to accomplish multiplex transmission - constituting a new kind of telemetry system. In this paper, the constitutive principle of Walsh function telemetry system is introduced, the Walsh function telemetry system has already been built, the experiments performed recently on this system and the results of flight experiment are comprehensively discussed.
    • A Four-State Trellis-Coded 8-PSK Modulation Computer Simulation

      Kopp, Brian; New Mexico State University (International Foundation for Telemetering, 1988-10)
      The continuing growth of the telecommunications industry has created a steadily increasing need for higher performance communications systems - systems that can transfer data at faster rates while meeting stringent bit error rate requirements. In the case of satellite and mobile communications these same systems must also maintain minimum size and power consumption requirements. To help implement this industry demand computer simulations of communications systems can be a viable tool. Simulators can be used to demonstrate feasibility while maintaining minimum research and development costs during the design phase of these new and more complex communications systems. One type of system where simulation has proved helpful has been trellis-codedmodulation (TCM). This paper documents a simulation of a four-state trellis-coded eight- PSK modulation scheme currently being researched at New Mexico State University (NMSU). In the past simulations of convolutionally coded schemes have used binary symbols in the decoding process. In TCM the Euclidean space components of the modulation scheme are used in place of the binary symbols. The simulator under development incorporates these Euclidean signal components which are taken from an eight-PSK signal constellation. Soft-decision maximum likelihood decoding using trellis trace-back techniques are then applied to the Euclidean signal components to recover the simulated transmitted data. The simulator supplies the user with the number of undetected errors generated during a simulation as well as the bit error rate for a given signal to noise ratio. This simulator is intended to provide an environment for investigating improved communication system designs and it is hoped that the results that are obtained from such telecommunication simulators will help satisfy the ever increasing demands of the telecommunications industry. It should be noted that the research being conducted at NMSU on TCM is being directed by Dr. Frank Carden. The development of the simulator was conducted by the author to assist Dr. Carden in the continuing investigation of TCM.
    • Functional Component Approach to Telemetry Data Capture Systems

      Sabia, Steve; Hand, Sarah; NASA, Goddard Space Flight Center (International Foundation for Telemetering, 1988-10)
      To support the telemetry data rates and meet the needs of telemetry data users in the next decade, telemetry data capture systems will have to be radically different from today's systems. At Goddard Space Flight Center, the Mission Operations and Data Systems Directorate is developing the capability to build user specific data capture systems from a library of high performance hardware and software elements that satisfy standard data capture processing requirements. One or more telemetry functions are encapsulated in a single standard open bus system (e.g. VME, Multibus II, NuBus etc.) with supporting software to form a user data capture system. Each subsystem module (card or board) includes a local microprocessor supplying on board intelligence and programmability for changing requirements. Many of these subsystem designs include custom very large scale integration (VLSI) components to increase speed while minimizing cost and size. A standard hardware and software interface to each card subsystem is employed to simplify system integration in the open system environment.
    • 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.
    • 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.
    • GPS: The Versatile Tool for Range Instrumentation

      Hoefener, Carl; Richardson, William; Interstate Electronics Corporation (International Foundation for Telemetering, 1988-10)
      The Global Positioning System (GPS) has made significant contributions in range instrumentation. It was the prime tracking method for both realtime range safety and metric tracking for the Trident II. Because of its many advantages, GPS will become the primary source of time, space, and position information (TSPI) on the ranges. Many activities requiring precision TSPI have already committed to GPS and others are planning on the application of GPS in the future for use on the ranges. GPS is also an extremely accurate time source, with timing accuracies of 10 nanoseconds obtainable worldwide. The range interoperability problem is solvable through the use of GPS as the TSPI source. There is little doubt that GPS will become the standard TSPI source for all test and training ranges.
    • A High Data Rate Airborne Rotary Recorder with Long Record Time

      Leung, Victor; DATATAPE Incorporated (International Foundation for Telemetering, 1988-10)
      Application of instrumentation recorders for data acquisition in hostile environments has for years been accomplished by means of longitudinal recorders specially designed for that application. DATATAPE Incorporated has been the leader in providing such recorders beginning with its MARS series. Two recent trends have impacted the applicability of these machines: the need for record times longer than can be provided by the longitudinal machines and the trend in the instrumentation industry to utilize digital recording techniques.
    • 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.
    • High Shock, Wideband, Miniature, Air Borne FM/FM Telemetry System

      Maoz, Michael; Svensson, Ake; Aydin Vector Division; Saab Missiles AB (International Foundation for Telemetering, 1988-10)
      Aydin Vector Division has received an order from Saab Missiles AB, Sweden, to develop an airborne, high shock, wideband FM/FM telemetry system. During 1985 (within a period of eight months) three such systems (FMT-780) were built and shipped to customer after successful testing in the plant. The testing included acceptance and qualification. Later on, the three systems were exposed to high shock testing/firing in Sweden. This paper describes the specifications of the system, the design approach that was used in order to meet these specifications, the systems conceptual mechanical and electrical structure, the packaging technique and some of the test results. As a result of the success of the program, Saab Missiles AB, awarded Aydin Vector Division with an additional order for sixteen, computer based, specially designed, miniature PCM/FM airborne telemetry systems. A paper describing these systems and the overall program is going to be published within the next two years.
    • High Speed Data Acquisition Systems

      Talmadge, Richard D.; Radmand, Mansour; Wright-Patterson Air Force Base; Aydin Vector Division (International Foundation for Telemetering, 1988-10)
      Air Force systems testing today requires that more and more data be acquired to a higher degree of accuracy and in fewer flights. This necessitates a new approach to dynamic data acquisition system design. In the past data acquisition organizations used either direct or FM recording techniques of one sort or another to acquire data for post test processing. This paper will outline the direction that this organization is taking to reduce the size of the installed system as well as the time and money required to maintain the system during the testing process. The system discussed provides a capability to acquire both static (DC) data and dynamic data up to 10,000 Hertz and has a dynamic range in excess of 120 dB.