McGiven, Fred A.; TIW Systems Inc. (International Foundation for Telemetering, 1990-11)
      TIW Systems has developed a modern, compact, modular, antenna controller (ACU) for telemetry, tracking, and communications antennas. The controller combines the functions of an antenna control unit, a position conversion/display chassis, and a polarization control unit. By using plug-in cards, a tracking receiver, autophasing control unit, tracking synthesizer, and other functions can be added. Depending on the requirements, the tracking receiver can be a simple wide-band steptrack receiver, or can be a full function phase-locked-loop (PLL) autotrack receiver. In the past, all this capability would have taken a large portion of an entire equipment rack. The unit uses modern microprocessor technology for digitally controlling the position and rate of the antenna. Advanced tracking modes and remote control can be added by connecting an external computer (PTIC) to one of the ACU’s serial ports. The PTIC also provides a user friendly operator interface through the use of high resolution color graphics and easy to understand menus.
    • Frame Synchronization At 300 Mbps And Beyond ...

      Wunderlich, Kristin; Chesney, Jim; Bennett, Toby; Goddard Space Flight Center; Ford Aerospace Corporation (International Foundation for Telemetering, 1990-11)
      While most current ground based space telemetry acquisition systems are designed for and support data rates up to a few megabits per second (Mbps), NASA’s Tracking and Data Relay Satellite System (TDRSS) can support downlink rates up to 300 Mbps. In addition, the Advanced TDRSS (ATDRSS) is expected to support rates up to 650 Mbps. These high data rates will be required to support NASA’s future large scale operational programs such as the Space Station Freedom and the Earth Observation System. At the Goddard Space Flight Center, a prototype Frame Synchronizer card is under development which will operate at a minimum of 300 Mbps while providing a full suite of programmable functions such as 32 bit correlation, search-check-lock strategy, bit slip tolerance, fly wheeling, etc. In addition, cumulative quality data generation, on-board self diagnostics, and status/control processing are all integrated in this single card design. This level of functionality and very high data rate is made possible by the design of NASA application specific Gallium Arsenide (GaAs) Very Large Scale Integrated (VLSI) circuits to support space telemetry data system standards specified by the Consultative Committee for Space Data Systems. This paper will describe functions performed by this card and its supporting VLSI components.

      Cipolla, Frank; Seck, Gerry; Datron Systems Inc. (International Foundation for Telemetering, 1990-11)
      Datron Systems has designed a dual band EHF autotrack feed. The feed allows simultaneous reception and autotracking at K band while transmitting at Q band. The feed design and operation is discussed.

      Crabtree, Steven B.; Feather, Bobby J.; Loral Data Systems (International Foundation for Telemetering, 1990-11)
      Telemetry applications today are requiring more and more computing power. The computing industry is responding to this need with more powerful machines. With these new machines the UNIX operating system is rapidly being accepted as the system of choice for the popular lowend and midrange RISC and CISC computers. The system discussed addresses the long standing question, “Can a complete UNIX system perform in a high-data-rate real-time environment?”. This paper describes the Loral Data Systems development of a Real-Time Data Transcription System (RDTS) built for Lawrence Livermore National Laboratory and TRW. This system utilizes a powerful telemetry preprocessor, internally bus-coupled to a real time UNIX host computer. An industry-standard VME-to-VME coupling provides an efficient setup, control and computational gateway for preprocessed telemetry data. This architecture illustrates a UNIX operating system to support a pseudo-real-time telemetry application.
    • Twenty-First Century Telemetry

      Montano, William G.; Rice, William A.; White Sands Missile Range, New Mexico (International Foundation for Telemetering, 1990-11)
      This paper addresses several areas of Telemetry instrumentation for the future. The possible 21st Century data formats and using the means made possible by technological advances to receive, record, and process telemetry data will be discussed. We will review the past, present and future systems and the changes to expect in the areas of Higher Data Rates, Greater RF Bandwidths, Multiple Object Test Scenarios, Telemetry Multiplex, Digital Microwave Radio Links, Lightwave Fiber Systems, Optical Disc Telemetry Data Recording, Data Security, and Global Telemetry via Satellite.
    • A Band-Width Limiting Circuit Improves Telemetry System Operation

      Lillie, Derek S.; LORAL CONIC (International Foundation for Telemetering, 1990-11)
      Present bandwidth limiters use a six-pole bessel filter approach to limit the power bandwidth of the transmitter to IRIG-106-86 requirements. However, the filter must be reconfigured if frequency changes in the data stream are desired for system requirement purposes, eg. adding encryption. The circuits set forth herein will provide for frequency change of the data stream while also providing a power increase by reducing the out of band power.

      Chi, Danny T.; Kodak Berkeley Research (International Foundation for Telemetering, 1990-11)
      Interleaving is a simple and effective way to improve the performance of an error correction scheme on a bursty channel. The interleaving of codewords will spread the effects of a long burst error into short bursts over several encoded sequences instead of a single codeword, and thus the chosen error correction scheme can correct them. This paper addresses a recently developed method, called helical interleaving ([1]) and presents some of its applications. The advantages of helical interleavers as compared with traditional interleavers are discussed. A relationship between helical interleavers and convolutional interleavers is also presented.

      Duffy, Harold A.; Naval Weapons Center, China Lake, CA (International Foundation for Telemetering, 1990-11)
      The goal of Word Selector hardware design is to place the selection and scaling of displayed data parameters under the control of destination observers. An initial design, discussed at the 1984 ITC, received its input telemetry data from a Compressor with modest throughput. The proliferation of nontraditional formats has forced the adoption of telemetry data preprocessors in place of simple Compressors. A new generation of Word Selectors is being developed with greater speed (1 million parameters/second), a serial data interface, and the equivalent scaling capability of traditional patch panel demultiplexers. The number of nonvolatile local setup files has been increased by 40%.

      GUISINGER, BARRETT E.; Datatape Technology Center (International Foundation for Telemetering, 1990-11)
      This paper describes the design and implementation of a low cost, analog, DC to 6 MHz bandwidth instrumentation recorder based on an industrial grade SVHS transport mechanism. The system is designed to meet all of it’s specifications utilizing standard offthe-shelf SVHS media. Novel digital processing is described allowing a fully timebase corrected recorder/reproducer to be housed in a one-half rack enclosure measuring 7"H x 8.5"W x 18"D and weighing less than 25 pounds.

      Vander Stoep, Donald R.; Ball Systems Engineering Division, San Diego, CA (International Foundation for Telemetering, 1990-11)
      Sensor slaying consists of pointing a secondary (slave) sensor to a target vehicle, coordinates of which are defined by measurements from a primary (master) sensor or set of master sensors. For typical range applications, the secondary sensor does not possess an autonomous tracking capability; thus, pointing commands for the secondary sensors must be derived from an external source, i.e., the primary sensor or system. A common example of a range slaving system consists of an optical sensor (e.g., a cine- of video theodolite) slaved to a tracking radar. In this instance, radar measurements (range, azimuth, elevation) are typically converted into a cartesian set (x, y, z), followed by the computation of the azimuth and elevation angles from the theodolite site to the designated point. These angles define commands for theodolite pointing.

      Wigfall, Glenn D.; US Armament Research, Development and Engineering Center (International Foundation for Telemetering, 1990-11)
      The last decade brought about the development of “smart” weapons and munitions that proved to be more efficient than conventional weapons based on their efficiency in the number of targets hit relative to the number hit using conventional weapons. The awakening of sensor-controlled, sensor-guided munitions technology has introduced a definitive need for telemetry instrumentation in developmental testing of this rapidly growing field. To satisfy the Army’s need for sensor-controlled, anti-tank munitions, several development programs are under way for the research and design of these systems. Telemetry has been a critical element in the development of these programs. From the program’s conception and through to its completion, the Armament, Research, Development, and Engineering Center-Telemetry Section has developed data acquisition systems to monitor the activity of such sensorcontrolled smart projectiles to support Army programs. This paper will discuss the development and use of a PCM telemetry system that has had tremendous success in use with these types of projectile programs in their sensor development and system integration stages. The application, albeit specific to these projectile programs, can be tailored to meet the needs of numerous test configurations within the Army or other organizations facing this need.

      Law, Eugene L.; Pacific Missile Test Center (International Foundation for Telemetering, 1990-11)
      This paper will describe the Pacific Missile Test Center’s (PMTC) approach to a computer controlled telemetry receive and record system. The advantages of this system include: fast, accurate equipment setup and interconnection, automatic verification of operational status, and simplified signal monitoring. PMTC personnel developed the system architecture and software. The system hardware is all unmodified off-the-shelf equipment. The main design drivers were cost, reliability, and minimizing the effect of any single point failure. The system uses many individual switches instead of a small number of large switch matrices. Manual patching capability has been maintained. This patching system provides a backup solution if all the computers get “zapped”. The patching system also provides increased signal routing flexibility.

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1990-11)
      Development of a next generation modular PCM system to satisfy a variety of applications for a decade or more resulted in a greater design effort than the use of the latest device technology to satisfy a current customer’s functional needs. Functionality of the existing product line, as well as competitive products, was coupled with a survey of users’ present and future needs, and their opinions of both the good and bad features of existing products. The survey covered system architecture, system throughput, signal conditioning, packaging, software, telemetry, recording and support. A phased development schedule implemented current customer requirements first, followed by development of ultimate system capabilities. Proof-of-concept prototyping proved extremely cost effective as significant changes and improvements in both mechanical and electrical designs resulted from the prototyping. Extensive internal design reviews permitted a wide range of engineering talent to contribute to the overall design. This major undertaking was started just over two years ago with mechanical prototyping and environmental testing of the new “Loaf-of-Bread” (LOB) packaging concept. The core system functionality, composed of 17 different types of functional modules, is now entering the production phase following full environmental qualification. Expanded system functionality is currently developed through proof-of-concept operational hardware which will be upgraded to production hardware within the year. The mechanical modularity achieved by the LOB package will permit system users to make low cost, periodic upgrades of key system functional elements by slice replacement without obsolescence of the majority of the users’ delivered hardware.
    • Antenna Modification for In-Flight Projectile Fuze Data

      Sandberg, Craig D.; US. ARMY ARMAMENT RESEARCH, DEVELOPMENT AND ENGINEERING CENTER (International Foundation for Telemetering, 1990-11)
      Microstrip antenna designs have gained importance due to the requirements and restrictions of projectile size and desired data. Most projectile testing programs require in-flight data during the entire trajectory. Original microstrip antenna designs created extensive variations in the antenna radiation pattern as the projectile was rotated about its axis. These variations led to distortion and total loss of data during critical events of a projectile fuze test. Developments and data that have led to modified designs in order to reduce these nulls will be discussed in the following sections.

      Jie, Cao; Qiu-cheng, Xie; Nanjing Aeronautical Institute, China (International Foundation for Telemetering, 1990-11)
      As the code length is increasing, the search of optimum group sync codes will be more and more difficult, even impossible. This paper gives the searching method of quasi-optimum group sync codes on the small subset of PN sequences -- CVT-TAIL SEARCHING METHOD and PREFIX-SUFFIX SEARCHING METHOD. We have searched out quasi-optimum group sync codes for their lengths N=32-63 by this method and compared them with corresponding optimum group sync codes for their lengths N=32-54. They are very approximative. The total searching time is only several seconds. This method may solves the problems among error sync probability, code length and searching time. So, it is a good and practicable searching method for long code.

      Xi-Hua, Li; Xinan Electronic Engineering Institute, China (International Foundation for Telemetering, 1990-11)
      This paper describes the technical principle that signals conversion, data-processing and data storage are directly carried out without filling up with the reference pulse for PPM and PPK (pulse position keying). By means of analysis for typical frame structure of PPM/PPK signals, a variety of math models of signal time relationship of the system were found, and based on this, a engineering way and a principle block diagram for signals conversion, data processing and data storage were given out.

      Daqing, Huang; Qiu-Cheng, Xie; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1990-11)
      In this Paper, the time-assisting code techique capable of defeating the repeat jamming is presented. The construction and antijamming performance of this technique are described and analyzed. This technique not only is robust to repeat jamming of Remote Control/Telemetring and Communication Systems, but also is used in multi-address remote control/ telemetring, multi-address communication and radar systems.
    • A State-of-the-Art Data Acquisition System

      Talmadge, Richard D.; Radmand, Mansour; Wright Research & Development Center; Aydin Vector Division (International Foundation for Telemetering, 1990-11)
      Recent developments in manufacturing technology have afforded a new capability in miniaturized instrumentation systems. The advent of ASIC (Application Specific Integrated Circuit) technology has provided the tools to implement very sophisticated signal conditioning circuits in micro-miniature instrumentation. This paper discusses the development of the Automatic Gain Ranging Amplifier (AGRA) and its implementation in the Aydin Vector MMSC-800 instrumentation package. Also discussed is the miniaturization of a 1553 Bus monitor, IRIG-B Time Code reader/accumulator and the development of a helical scan miniature tape recording system capable of recording 2+ hours of 3.4 Mbps data. The paper concludes by giving applications for and benefits of using this new state-of-the-art instrumentation.
    • Enhancing the Capabilities of Digital Bit Synchronizers

      Windingland, Kim; Loral Instrumentation (International Foundation for Telemetering, 1990-11)
      Bit synchronizers have traditionally provided very little feedback to the user. This paper describes features that give the user a window into the quality of the signal and verification that the bit synchronizer is performing properly. In addition, this paper describes a feature that automates some of the bit synchronizer’s functions to maximize its performance. The features described are: (1) a Built-in Oscilloscope (BIO) to provide the user with a visual representation of the input signal; (2) a Link Quality Analyzer (LQA) to provide the user with a quantitative measure of the input signal’s quality (signal-to-noise ratio (SNR) measurement); (3) a Built-in Test (BIT) to provide confidence in the unit’s functional and bit error performance; and (4) an Automatic Adaptive Control (AAC) to maximize acquisition and bit error rate performance.

      Law, Eugene L.; Pacific Missile Test Center (International Foundation for Telemetering, 1990-11)
      This paper will present the results of a study to correlate tape dropouts and data quality. A tape dropout is defined in the Telemetry Standards as “a reproduced signal of abnormally 1 low amplitude caused by tape imperfections severe enough to produce a data error” Bit errors were chosen as the measure of data quality. Signals were recorded on several tracks of a wideband analog instrumentation magnetic tape recorder. The tape tracks were 50 mils wide. The signal characteristics were analyzed when bit errors or low reproduce amplitudes were detected.