• LOW-POWER FAULT-TOLERANT MICROPROCESSOR-BASED DISTRIBUTED ARCHITECTURE FOR ON-BOARD SIGNAL PROCESSING

      Haas, W. H.; Liao, H. H.; Schoknecht, W. E.; Rockwell International (International Foundation for Telemetering, 1983-10)
      Numerous future space-based systems are being conceived that will require the on-board processing of a volume of data many orders of magnitude greater than the current state-ofthe- art. Such systems must in addition be extremely low power and autonomously fault recoverable. This paper describes a microprocessor-based distributed architecture that has been evolving as a solution to this problem. This proposed architecture features three subarchitectures: synchronous pipeline, dedicated-channel microprocessor array, and multiplebus oriented microcomputer array; as well as internal data compression, distributed control and self testing, and a building block approach to system implementation. Emphasized is the roll of microprocessors in this architecture and the challenge of reducing the overhead required by fault-tolerant processing.
    • A MICROMINIATURIZED HEART MONITORING SYSTEM FOR ASTRONAUTS

      West, Laurice J.; Ommitek, Inc. (International Foundation for Telemetering, 1983-10)
      The heart monitoring system used by the astronaut in his space walk from the shuttle used as a portion of the instrumentation, a voltage controlled oscillator and a matching discriminator to encode and decode the heart waveform. In addition to small size, low power, and high reliability, there were additional requirements for greater than normal signal rejection by the input filter of the discriminator and cost reduction by limiting the number of different semiconductors used in order to keep lot qualification costs low. The circuits were fabricated using thick film hybrid techniques. The circuit designs, fabrication techniques and packaging will be described.
    • ADVANCED TT&C FOR THE AIR FORCE SATELLITE CONTROL FACILITY CONCEPTUAL OVERVIEW

      Carroll, James T.; The Aerospace Corporation (International Foundation for Telemetering, 1983-10)
      The Department of Defense will be moving their essential space resources into the EHF spectrum which, together with new signal structures, will counter the impacts of jamming, nuclear effects, and electronic intelligence intercept. The Air Force Satellite Control Facility (AFSCF) project for incorporating the new Satellite Data Link Standards (SDLS) into its existing antenna and communication network is described. Also, the signal structure concepts, system architecture, EHF user programs, interoperability factors, and finally, implementation plans. Taken together, these factors will implement a new SDLS Military Standard for space links.
    • TRANSPORTABLE TT&C TERMINALS: CONCEPTUAL SYSTEMS DESIGN CONSIDERATIONS

      Kannard, Keith B.; The Kannard Company (International Foundation for Telemetering, 1983-10)
      Sustaining operations of critical satellites throughout the modern conflict spectrum has become a key issue in our national defense posture. Ground and air transportable Telemetry, Tracking and Control (TT&C) terminals are a viable solution when their design addresses the broad systems requirements that are dictated by today’s needs. Rapid deployment and quick deactivation of these systems along with related systems design requisites need to be examined. Autonomous as well as internetting capabilities, modular and flexible approaches for operational, reliability and maintainability needs, commercial versus military hardware and mission interoperability are systems design concepts that are considered.
    • PRELIMINARY TEST RESULTS OF THE ELECTRONIC SWITCHING SPHERICAL ARRAY ANTENNA

      Kudrna, Ken; Ball Aerospace Systems Division (International Foundation for Telemetering, 1983-10)
      An Electronic Switching Spherical Array (ESSA) Antenna has been developed for low obiting spacecraft requiring medium gain (+13 dBic) transmit and receive relay capability through the Tracking and Data Relay Satellite Systems (TDRSS). This 145 radiating element antenna is steered with a microprocessor controller by selecting arrays of 12 elements at a time. Approximately 1800 beams can be selected for near hemispherical coverage. The primary method for evaluating this antenna is a composite Radiation Distribution Plot (RDP).
    • USING MANCHESTER ENCODED DATA TRANSMISSION FOR ROV TELEMETRY

      Mackey, Lawrence A.; Undersea Vehicle Department (International Foundation for Telemetering, 1983-10)
      The communication link between the surface operator and an underwater Remote Operated Vehicle (ROV) provides the critical function of monitoring and controlling the movements of the ROV. If the communication link is weak, the ability to operate the ROV is weak. The reliability of that communication link can be significantly improved by the use of Manchester coding in time division multiplex (TDM) data telemetry systems that provide a self-clocking method of data transmission. This method of data transmission is presently used on both military (MIL-STD-1553), and commercial aircraft supplying data communication between subsystems onboard. One important part of telemetry that this paper discusses is the various signals that must be telemetered between the surface and the ROV. The complexity of sending these signals varies with the type of signal and the requited quality/resolution required at the opposite end of the line. Also of importance is the media over which the data is being transmitted. Transmitting data up and down long umbilical cables is not unlike data transmission elsewhere, however there are subtle potential problem areas that most other systems are able to avoid. The possible methods of transmission range from using a twisted pair of wires, to the state of the art sophistication of fiber-optics. Each method has merits and pitfalls that the potential user must be aware of before trying to use them.
    • STANDARD FORMAT DATA UNITS: TOOLS FOR AUTOMATIC EXCHANGE OF SPACE MISSION DATA

      Willett, James B.; Jet Propulsion Laboratory (JPL) California Institiute of Technology (International Foundation for Telemetering, 1983-10)
      Two of the tools necessary for automated exchange of space mission data sets are, (1) a set of standard formatting rules for the data sets, and (2) a standard computer-readable language with which to describe the data. These two tools are used to create the Standard Format Data Unit (SFDU). The NASA/JPL proposal for creation and utilization of SFDUs is presented, and its relationship to recent recommendations from the Consultative Committee for Space Data Systems (CCSDS) is discussed. Several current and planned implementations of the SFDU concept among major space flight projects will be identified.
    • LOW COST, LIGHTWEIGHT, SINGLE AXIS TRACKING SYSTEM FOR UNMANNED VEHICLE APPLICATION

      Sullivan, Arthur; Turner, William C.; Electro Magnetic Processes, Inc. (International Foundation for Telemetering, 1983-10)
      Recent events in the Falkland Islands, and in Israel/Lebanon, have made the tactical use of unmanned airborne vehicle systems a practical reality The control of the unmanned vehicles requires a radio uplink, a downlink for vehicle position determination, for telemetering monitored events and functions, and, in some instances, transmission of television or other information. While for some situations the ground antenna can be fixed, the majority of today’s applications require a steerable antenna. This is dictated by the fact that a high gain (and therefore, narrow beam) antenna is required for maximum range, and that for most scenarios, vehicle position must be determined. The increasing use of unmanned vehicles indicates the need for a low-cost tracking antenna system. Use of the tracking antenna in transportable and/or mobile systems calls for a lightweight system. A two-axis antenna, in addition to being heavy, is more than twice the cost of a single-axis tracking antenna system. Slant range of the vehicle is determined by the use of a ranging tone and ground range is determined by comparing altitude data telemetered back from an on-board altimeter with slant range. Complete positional data are obtained given the ground range and the bearing angle from the singleaxis tracking antenna. A microprocessor-based antenna control unit allows all systematic errors of the antenna system to be calibrated out of the angle data. A binomially fed, linearly polarized, folded pillbox horn antenna, having extremely low sidelobes, permits wide angle acquisition, and high elevation angle tracking without introducing bearing angle error. The use of graphite fiber materials for antenna and rotator construction provides savings both in cost and weight. A newly developed lightweight and low-cost single-axis tracking antenna that utilizes all these techniques is described in this paper.
    • TECHNIQUES FOR ACQUIRING DIGITAL DATA FROM INTELLIGENT SUBSYSTEMS

      Gilje, Harold B.; Nicolais, Raymond F.; Aydin Vector Division (International Foundation for Telemetering, 1983-10)
      There is an ever-increasing need for intelligent sub-systems onboard airborne and ground vehicles. With this intelligence comes asynchronous bus communications under the control of various industry standards and specifications. As a result, two telecommunications needs have developed; from a telemetering viewpoint, that of acquiring data from the various intelligent sources and time-division multiplexing that data with classic analog instrumentation, and, from an intravehicle communications viewpoint, that of providing a means for transfer of information between two dissimilar sub-systems. A systematic breakdown of the necessary elements to link, synchronize, sort, interpret, store, merge and control such data is examined. Proven approaches to handling data from both standard (ARINC, MIL-STD-1553, IEEE-488, etc.) and specialized subsystems is overviewed from an instrumentation perspective.
    • DIGITIZING SATELLITE GROUND STATION TT&C SUBSYSTEMS

      Chen, Thomas J.; Ford Aerospace & Communications Corporation (International Foundation for Telemetering, 1983-10)
      There are many advantages to implementing satellite ground station TT&C functions using digital LSI and VLSI technology: increased reliability, reduced size, weight and power and enhanced performance. The functions of a satellite ground control station that could be digitized in the future are identified. The evolving capabilities in digital chip technology are reviewed to indicate how they would be applied to satisfy these TT&C functions. Fundamental performance limitations of these technologies are also identified.
    • TRUTH TRAJECTORY ESTIMATION FOR GLOBAL POSITIONING SYSTEM USER EQUIPMENT TESTS

      Lt.Col. Kruczynski, Leonard R.; U.S. Army Yuma Proving Ground (International Foundation for Telemetering, 1983-10)
      Testing of NAVSTAR Global Positioning System (GPS) user equipment at the U.S. Amy Proving Ground (YPG) requires accurate position and velocity information. GPS position accuracy is 15 meters spherical error probable and velocity accuracy is .1m/sec RMS per axis. Proper evaluation of GPS user equipment requires position and velocity information more accurate than the equipment under test. YPG users laser trackers to develop a real-time estimate (RTE) of the trajectory. Independent analyses show that the RTE accuracy is about 3m and that velocity accuracy is about .25/m sec overall. This paper describes the development of the RTE starting from the raw laser measurements to the calculation of position and velocity in a local coordinate frame. Included is a description of the filter. The paper also discusses the methods used to verify the accuracy of the RTE.
    • TELEMETERING AND COMMUNICATIONS USING PROGRAMMABLE CONTROLLERS

      SCHIFTER, TRUDI RAE; GENERAL ELECTRIC COMPANY INDUSTRIAL SALES DIVISION SAN FRANCISCO, CALIFORNIA (International Foundation for Telemetering, 1983-10)
    • REAL-TIME PCM PROCESSING AT THE TONOPAH TEST RANGE

      Sherman, Stephen; Tebbs, J Daniel; University of Nevada; Sandia National Labs (International Foundation for Telemetering, 1983-10)
      PCM data at the Tonopah Test Range (TTR) is processed and displayed in real-time on a Perkin-Elmer 8/32-D computer system. Up to four links can be processed concurrently, with input data coming from telemetry PCM/PAM decommutators and multichannel ADC systems. Special software is used to strip out an embedded PCM format and input the data as a simulated PCM link. Off-line interactive programs are used to specify the PCM data format and create the displays. This capability allows a wide variety of PCM formats to be specified, and displays can be easily configured to fit testing requirements.
    • A PORTABLE JAMMING SYSTEM TO EVALUATE THE PERFORMANCE OF L BAND RADIO SYSTEMS IN AN EW ENVIRONMENT

      POSNER, RICHARD D.; O’LEARY, JAMES N.; 3dbm SYSTEMS, INC.; THE AEROSPACE COMPANY (International Foundation for Telemetering, 1983-10)
      This paper describes a system which has been developed to simulate a number of potential EW environments. The system consists of a net of portable jammers remotely controlled from a single command and control center. Each portable jammer can be adapted for ground or air utilization and each unit includes various types of noise sources, a power amplifier and an integral transmit antenna. The paper provides a detailed description of the jammer hardware. The antenna is a specially developed conical horn back helix. An 80 Watt nominal solid state power amplifier is described along with the control system which allows precisely controlling and monitoring the RF Output power level. Circuitry to develop noise modulation is explained as well as the AC/DC Power System which allows the jammer to be used with a variety of Power Sources. Control of the jammer via a centrally located RF transmitter addressing individual remote receivers is discussed. Overall system performance in terms of Noise Power Spectral Density, level variations and control of spectrum are described. Finally, a description is given of the use of the portable jammer system to emulate possible jamming environments which could be encountered in tactical GPS applications.
    • LINK PERFORMANCE ANALYSIS AND MONITORING: A UNIFIED APPROACH TO DIVERGENT REQUIREMENTS

      Thom, Gary A.; Snyder, Edwin; AYDIN MONITOR Systems (International Foundation for Telemetering, 1983-10)
      Link Performance Analysis and real-time monitoring are generally covered by a wide range of equipment. Bit Error Rate testers provide digital link performance measurements but are not useful during real-time data flows. Real-time performance monitors utilize the fixed overhead content but vary widely from format to format. Link quality information is also present from signal reconstruction equipment in the form of receiver AGC, bit synchronizer AGC, and bit synchronizer soft decision level outputs, but no general approach to utilizing this information exists. This paper presents an approach to link tests, real-time data quality monitoring, and results presentation that utilizes a set of general purpose modules in a flexible architectural environment. The system operates over a wide range of bit rates (up to 150 Mbs) and employs several measurement techniques, including P/N code errors or fixed PCM format errors, derived real-time BER from frame sync errors, and Data Quality Analysis derived by counting significant sync status changes. The architecture performs with a minimum of elements in place to permit a phased update of the user’s unit in accordance with his needs.
    • A SOLID-STATE C-BAND POWER AMPLIFIER FOR COMMUNICATIONS SATELLITES

      LaPrade, J. Nicholas; RCA Astro-Electronics (International Foundation for Telemetering, 1983-10)
      A solid-state power amplifier now routinely replaces the traveling-wave tube amplifier in C-band communications satellites. The immediate benefit of superior performance is realized by increased transponder capacity. Long-term benefits of higher reliability and reduced production costs are also projected. This paper describes salient features of the first solid-state power amplifier to fully replace the traveling-wave tube amplifier in spaceborne transponders. The 8.5-watt, 60-dB gain amplifier employs a chain of gallium-arsenide field-effect transistors to provide a 160-MHz usable bandwidth within the 3.7- to 4.2-GHz downlink band. Data typical for this amplifier are presented. The key parameters of efficiency, intermodulation distortion, and phase effects are described in detail. The amplifier is being manufactured for numerous communications satellite programs. Aspects of reproducibility and automated testing at the various stages of amplifier production are addressed. Forty-eight amplifiers are now operational at geosynchronous altitude with several times that number scheduled for launch within the next few years.
    • NEW APPROACHES TO TRANSDUCER EXCITATION AND CONDITIONING

      Price, Edward J.; Ricker, William G.; Aydin Vector Division (International Foundation for Telemetering, 1983-10)
      Transducer excitation and conditioning has continually influenced the size, power consumption, complexity, and weight of miniature data acquisition and multiplexing systems. Here we examine a new approach to the excitation and conditioning of transducers which have traditionally been formed into a wheatstone bridge configuration. This approach has been successfully utilized in new miniature systems to reduce size, power, and weight while not adversely effecting the function or accuracy. Thermocouple measurements have also presented a significant conditioning problem, in that reference junction compensation and a measurement offset temperature must be provided for each thermocouple measurement. We show here an approach which, through the use of a single reference junction compensation and offset amplifier, has achieved significant improvements in the collection of temperature data.
    • NEW DIGITAL-INPUT TRANSMITTER FOR MISSILE TELEMETRY

      Rieger, James L.; Woodworth, Paul H.; Naval Weapons Center (International Foundation for Telemetering, 1983-10)
      Telemetry for aircraft and missiles has been in use by the military and its suppliers since the 1950’s, using a variety of frequencies and formats. The relative availability and versatility of digital electronics obviates use of pulse-code modulation (PCM) schemes, rather than analog-based formats used more commonly in the past. The digital-input transmitter described accepts binary format directly from a TTL source and has applicability in both standard telemetry and encrypted systems.
    • THE GRUMMAN ADVANCED TELEMETRY PREPROCESSOR

      Sangl, Donald; Silberto, Joe; Grumman Data Systems Corporation (International Foundation for Telemetering, 1983-10)
      The Grumman Automated Telemetry System (ATS) was one of the first computer based real-time flight test systems. It delivered real-time answers enabling Grumman to cost effectively meet its aircraft test objectives since 1970. Since then, aircraft systems have become more sophisticated with higher data rate requirements and with more on-board processing. Analysts have become more involved with defining man/machine interfaces and more sophisticated in their demand for real-time test data processing system. This paper provides an insight into the analyses and design trade-offs made when the first major section (The Preprocessor Subsystem) of the ATS was to be replaced. It proceeds from the requirements definition, through acceptance test results of the Advanced Telemetry Preprocessor (ATP). Emphasis is placed on the ATP hardware configuration, the subsystem software and the design/build cycle. System test results and a look into the future regarding planned applications and possible performance upgrades are summarized. The ATP is the first step in a series of planned upgrades of the ATS which will enable it to meet the flight test user’s demand for increased volume, sophistication and user-friendly interaction.
    • REALIZING HIGH-RATE SYSTEMS: A TECHNOLOGY STUDY REDUCED TO PRACTICE for LANDSAT-D

      Grebe, David; AYDIN MONITOR Systems (International Foundation for Telemetering, 1983-10)
      Generalized use of ECL in telemetry systems requires the reduction of transmission line theory, power distribution, topology considerations, and device characteristics to an implementation that is reproducible, permits rapid changes, and is cost effective. Bringing high data rates (up to 150 Mb/s) to everyday status was one goal in the development of a LANDSAT-D format synchronizer. The unit had to perform preamble and minor frame synchronization followed by decoding, decommutation, and formatting at the Thermatic Mapper real-time rate of 85 Mb/s. To additionally handle MSS and standard telemetry, as well as stream simulation and bit error rate measurements, a generalized solution was required. This is in opposition to a specially designed unit to fulfill only LANDSAT mission requirements. To produce the unit best suited to telemetry disciplines where formats change rapidly, the unit was implemented using wire wrapped modules with the stated goals realized.