• 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.
    • 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.
    • Off-Loading the Host Computer Through Flexible DMA Interface

      Nicolo, Stephen J.; Aydin Monitor Systems (International Foundation for Telemetering, 1988-10)
      As data rates and system throughput requirements continue to increase, more and more attention must be given to ways of off-loading the host computer by shifting tasks to the front-end preprocessing subsystem. In addition to some of the more common tasks like data compression and EU conversion already performed in the front end, there is the time consuming task of organizing telemetry data. Once relieved from this secondary task the host can solely attend to its primary task of application processing. This paper describes an intelligent DMA interface (CPI007) which permits the automatic building of various types of array buffers in the host computer. This flexible high-speed device uses an EPROM based, bit slice microengine utilizing parameters stored in its operational store RAM during setup to build the array buffers. The interface is implemented on a single module in the front-end preprocessing subsystem and was developed for those mainframe computers that can be configured to accept address/data inputs for DMA to system memory (e.g. Gould Sel, DEC). With this type of architecture, algorithms may easily be written to accommodate a wide variety of data organization and transfer requirements. Along with the technical description of this device, actual data array buffering problems and solutions will also be addressed in this paper.
    • 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.
    • 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.
    • A Survays On Fading Channel Over West - Java Area for Flight Test Radio Telemetering Purposes

      Soelaiman, Adi Dharma; Pudjiastuti, Rina; Indonesian Aircraft Industry Ltd. (International Foundation for Telemetering, 1988-10)
      This paper discusses one approach to determine a characteristic of West - Java's air and ground segment as a block-box to accomodate radio waves propagation, especially in L-band ranges, by evaluating both the topographical data and radio reception pattern as measured from ground based telemetry receiving-end system. All the measured signals are random and assumed to be stationair and ergodic. In order to characterize the channel for polarization diversity reception, some statistical analysis are applied to the signal strength measured of both - RHCP and LHCP components of 1531 MHz propagated waves as transmitted fr om NC212-200 PK-NZJ-aircraft. Some computer calculated correlograms of measured data are shown herewith, it is focused for a certain radio corridor at radial 265E relative to the ground based receiving antenna. More over some curves of predicted multipath gain factor are also presented to gain more theoretical back ground. When this paper is written, a further field experiments on the matter concerned is beeing conducted.
    • 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.
    • 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.
    • 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.
    • 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.
    • The Searching Method of Optimum Frame Synchronization Codes Based on the Synthetic Optimum Criterior

      Jie, Cao; Qiu-Cheng, Xie; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      This paper gives a new searching criterior of optimum or suboptimum frame sync codes that escapes from unnecessary calculation and presents a searching method. It has a great improvement on existing methods (exhaustion technique, and so on) and the computing time is decreased by 1~2 order of magnitudes. Finally, the optimum frame sync codes with the length n from 7 to 32 are given.
    • 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.
    • Data Transport Subsystem: The SFOC Glue

      Parr, Stephen J.; California Institute of Technology (International Foundation for Telemetering, 1988-10)
      The Data Transport Subsystem (DTS) is a core subsystem of SFOC which holds together the GIFs, TISes, DMDs, DTVs and other SFOC application subsystems allowing them to operate in a distributed LAN based workstation environment. DTS does this by providing two primary features. The first feature is transparent local and remote interprocess communication. The communications interface is identical between two application subsystem processes whether they're running in the same machine or different machines. The second feature is the Logical Name Server, which makes connections on a name basis without regard to location or network topology. With these two features SFOC becomes a distributed system. Processes within a subsystem can even be distributed to perform load leveling and enhance system performance. Distribution fosters the use of redundancy and hot backups by allowing nodes to serve multiple purposes. Distribution allows isolation of mission telemetry while providing shared use of a common database. It supports the SFOC goal of off-the-shelf hardware expansion and upgrade. DTS provides an open-close-send-receive model of interprocess communication. It offers three types of service: virtual circuit, datagram and broadcast. The virtual circuit service supplies a full duplex path between communication endpoints and guarantees data integrity. The datagram service allows many communications endpoints to send to one endpoint. This is useful for sending status to a central process. The broadcast service allows a process to send to many receiver endpoints. This can be used for continuous monitoring of telemetry streams by multiple processes.
    • A Programming Parallel Real-Time Process Data Flow Telemetry System

      Da-qing, Huang; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      In this paper, a programming parallel real-time process data flow telemetry system is presented. What we developed recently is a advanced telemetry system which can process multi-data-flow of multi-target for mulit-user at the same time. It can be used in RPV, missile and others. Its main characteristics are as follows: Input radio frequency is S wave band (multi-dot frequencies). In telemetry front-end, the chip microprocessor is used to make demodulation and decode. Telemetry preprocessor consists of parallel distributed chip microprocessor mould plates (bus link). There are menu shope man-computer dialogue, figure display, intelligence display and intelligence self-diagnosis in this system. Now, we have developed data compress mould plate, floating-point arithmetic mould plate, derive calculation mould plate and signal process mould plate etc. The main computer is VAX-II.
    • 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.
    • Decommutation of Mil-Std 1553B Data from EA6B or IRIG Telemetry Formats

      Devlin, Steve; Aydin Monitor Systems (International Foundation for Telemetering, 1988-10)
      With the acceptance of Mil-Std-1553B by vehicle and weapons industries a wealth of new information is available for vehicle testing. In the past, selected data was extracted and included in a standard PCM telemetry stream. But only the selected data was made available. In EA6B and in the proposed IRIG Standard, multiple Mil-Std-1553B data busses are combined with identifying control bits in a single PCM telemetry stream. All of the information traveling each bus is available to the ground station. These formats share a number of features. One is that for each Bus the Mil-Std-1553B word appears in the same order in the telemetry stream. Another is that individual data words do not depend on their position in the telemetry stream for identification, but they do depend on the control information associated with the current message to give meaning to the data words. An efficient approach is outlined for identifying, selecting and routing individual measurements, messages, and/or all Mil-Std-1553B bus information to processes and I/O devices in a data flow environment.
    • 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.
    • 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.
    • Parallel Bus Implementations in Satellite Communications Systems

      Yun, Paul M.; E-Systems (International Foundation for Telemetering, 1988-10)
      As the volume of linkages in the satellite communications systems increases, the parallel bus between the various processors of the satellite becomes a bottle neck to transfer the commands and data. The remedies to this problem are trivial in the ground stations; however, this problem imposes severe restrictions in parallel bus implementation of the satellite communications systems. The most severe restriction is the minimization of wire connections in the physical layer to minimize the weight, size and power consumption, and also to maximize the reliability. Another restriction is the flexibility in the link layer to adapt the different characteristics of the command and data messages. In this paper, the implementation to overcome the imposed restrictions in both physical and link layer of the parallel bus will be discussed.