O’Connell, Richard; Myriad Logic, Inc. (International Foundation for Telemetering, 1997-10)
      For many years VME has been the platform of choice for high-performance, real-time data acquisition systems. VME’s longevity has been made possible in part by timely enhancements which have expanded system bandwidth and allowed systems to support ever increasing throughput. One of the most recent ANSI-standard extensions of the VME specification defines RACEway, a system of dynamically switched, 160 Mbyte/second board-to-board interconnects. In typical systems RACEway increases the internal bandwidth of a VME system by an order of magnitude. Since this bandwidth is both scaleable and deterministic, it is particularly well suited to high-performance, real-time systems. The potential of RACEway for very high-performance (200 Mbps to 1 Gbps) real-time systems has been recognized by both the VME industry and a growing number of system integrators. This recognition has yielded many new RACEway-ready VME products from more than a dozen vendors. In fact many significant real-time data acquisition systems that consist entirely of commercial-off-the-shelf (COTS) RACEway products are being developed and fielded today. This paper provides an overview of RACEway technology, identifies the types of RACEway equipment currently available, discusses how RACEway can be applied in high-performance data acquisition systems, and briefly describes two systems that acquiring and capturing real-time data streams at rates from 200 Mbps to 1 Gbps using RACEway.

      Lautzenhiser, Lloyd L.; Emhiser Research, Inc. (International Foundation for Telemetering, 1997-10)
      A 10- or 20-Watt, L- or S-band transmitter commonly consumes the majority of the available DC power on a telemetry pack -- often more than all the remaining components combined. A new family of transistors allows a substantial increase in DC to RF efficiency without the use of complex and costly switching regulators. With ever increasing data rates requiring more RF bandwidth (and correspondingly lower receiver sensitivities), transmitters using these transistors offer twice the RF power at little or no increase in DC current. Alternately, in other situations such as observation balloons, the same RF power can be achieved with approximately 40% less current resulting in significantly longer mission life. This paper describes the method for achieving higher efficiency transmitters using new LDMOSFETs.

      Rice, Michael; Law, Eugene; Brigham Young University; NAWCWPNS (International Foundation for Telemetering, 1997-10)
      This paper describes the two main causes of fading encountered at test ranges. The first cause of fading results from nulls in the transmit antenna gain pattern. Variations in the received signal level are a result of changes in the gain pattern as the spatial relationship between transmitter and receiver change. The second cause of fading is due to multipath interference. This occurs when multiple copies of the transmitted signal with different delays arrive at the receiver and are phased relative to each other so that destructive interference occurs.

      Cebik, James A.; Connor, William J.; Boeing/Sikorsky Combined Test Team (International Foundation for Telemetering, 1997-10)
      The RAH-66 Comanche flight test program required a state of the art Airborne Data Acquisition System consisting of: 1) A modular distributed system that uses a series of software programmable building blocks capable of signal conditioning all types of sensors. 2) A digital multiplexing system capable of combining various types of digital streams at high rates including Synchronous and Asynchronous PCM, MIL-STD-1553B, and RS-422 data streams. 3) A Data Combiner Unit that accepts synchronous PCM data streams from one to eight sources at 4 MBPS or less and a frame size of up to 8128 words each that outputs four independent PCM streams at 8 MBPS or less and a frame size of up to 16384 words. 4) A Data System Control Unit that controls the tape recorder, serves as the interface to the Pilot’s Control Unit and monitors/reports status of the data acquisition system to the Pilots Control Unit. 5) An Airborne Computer that provides the control and interface to the pilot & copilot instrumentation displays. 6) A Cockpit Instrumentation Pilot Display System consisting of a Main Unit Multi- Function Display, a Load Factor/Hub Moment Display and a Right Wing Flight Control Position Display. The Main Unit Multi-Function Display has the capability to display multiple graphic pages generated by the Airborne Computer. 7) The ability to record high speed avionics buses from the (Mission Equipment Package) MEP such as MIL-STD-1553B, (High Speed Data Bus) HSDB, (Processor Interconnect) PI Bus, (Data Flow Network) DFN and PCM utilizing the Ampex DCRsi-107 Tape Recorder.
    • Analysis of JDAM Tests at China Lake

      Rice, Michael; Welling, Kenneth; Brigham Young University (International Foundation for Telemetering, 1997-10)
      This paper examines telemetry signal levels of the Joint Direct Air Munition (JDAM) tests at China Lake NAWC. Significant received signal level variations were observed as the munition approached impact. This paper presents and examines two simple multipath models to explain the received signal variations. The first model assumes a flat earth and a single specular multipath reflection. The second model uses the actual contour of the earth and considers a number of specular multipath reflections. The first model (which assumes the single multipath reflection) more accurately reproduces the variations in the received signal level than the second.
    • Antenna Gain Pattern Effects on Multipath Interference in Aeronautical Telemetering

      Rice, Michael; Friend, Daniel H.; Brigham Young University (International Foundation for Telemetering, 1997-10)
      This paper examines the effect of antenna gain pattern on multipath fades for a typical aeronautical telemetry system. Assuming a parabolic reflector antenna at the tracking station and a single specular reflection as the source of multipath, an expression for the fade depth which incorporates the attenuating effects of the antenna gain pattern is derived. A representative example is presented which demonstrates the utility of the expressions derived.

      Jian, Zhang; Junxin, Ge; Futang, Zhang; Xinan Electronic Engineering Institute (International Foundation for Telemetering, 1997-10)
      In this paper, the basic ideas of advanced Spread Spectrum Unified Tracking Telemetry & Command System are introduced, the approaches and strategies to reject narrowband interference, multiple access interference and multipath interference are discussed. With effective interference-rejection, the safety and robustness of SS-UTTCS will be improved enormously.

      Eng, Thomas; The Aerospace Corporation (International Foundation for Telemetering, 1997-10)
      The relative anti-jam (AJ) performance of several diversity combiners are investigated. The modulation is 8-ary frequency-shift-keying (FSK), the demodulation process consists of energy detection of the eight frequency bins at each hop and the subsequent combining of detector outputs. Three combiners are considered : the linear combiner, where the detector outputs of each hop (corresponding to the same frequency bin) are summed without any processing; the self-normalized combiner, where the eight detector outputs of any particular hop are normalized so that they add to unity; and the max-normalized combiner, where the eight detector outputs of any hop are divided by the maximum value among those eight outputs. Results indicate that under worst-case tone jamming, the selfnormalized combiner performs the best, the max-normalized combiner second best, and the linear combiner performs the worst among the three.

      Harris, Carol; Mascari, Michele; Rice, Kevin; Smith, Jeff; Steedman, John (International Foundation for Telemetering, 1997-10)
      The Asynchronous Transfer Mode (ATM) Conversion Device (ACD) System is based on state-of-the-art ATM technology. The system interfaces between high-rate ECL/RS-422 raw data bitstreams and Synchronous Optical Network (SONET) OC-3 fiber. The SONET OC-3 interface uses ATM Adaptation Layer Type Five (AAL5) format. The system exceeds its 50 Mbps raw data, single stream requirement and provides single stream raw data throughput at rates up to 75 Mbps. With ATM and SONET packaging overhead, this translates into 90 Mbps on the OC-3 fiber. In addition to high-rate throughput, the system provides multiplexing and demultiplexing of multiple stream throughput based on the ATM cell header Virtual Path and Virtual Channel Identifier (VPI/VCI) values. The system is designed with the flexibility to provide between three and six throughput channels. All of which are multiplexed/demultiplexed to and from the same OC-3 interface. Multiple stream cumulative raw data throughput rates of up to 80 Mbps, or 96 Mbps on the fiber, have successfully run.

      Seeds, Michael A.; Franklin and Marshall College (International Foundation for Telemetering, 1997-10)
      Astronomers now communicate over Internet with robotic astronomical telescopes using a specially designed instruction set. ATIS, Automatic Telescope Instruction Set, is designed to communicate specific, technical instructions to a robotic telescope, facilitate data retrieval and analysis, support a wide range of data formats, and also convey preference information that describe the astronomers general needs for data acquisition. Over a dozen telescopes now use ATIS and more are under construction.

      Swartwout, Michael A.; Kitts, Christopher A.; Stanford Space Systems Development Laboratory (International Foundation for Telemetering, 1997-10)
      Stanford’s Space Systems Development Laboratory is developing methods for automated spacecraft health operations. Such operations greatly reduce the need for ground-space communication links and full-time operators. However, new questions emerge about how to supply operators with the spacecraft information that is no longer available. One solution is to introduce a low-bandwidth health beacon and to develop new approaches in on-board summarization of health data for telemetering. This paper reviews the development of beacon operations and data summary, describes the implementation of beacon-based health management on board SAPPHIRE, and explains the mission operations response to health emergencies. Additional information is provided on the role of SSDL’s academic partners in developing a worldwide network of beacon receiving stations.
    • Automating Signal Conditioning Setup Through Integration with Sensor Information

      Tate, Jeffrey J.; Caterpillar Inc. (International Foundation for Telemetering, 1997-10)
      Caterpillar Inc. has been testing construction and mining equipment using Computerized Analysis Vans for two decades. During our latest van upgrade, we chose to move to PCM/FM from FM/FM mainly to increase the channel count. We also replaced our old signal conditioning that used span and balance potentiometers with computer programmable signal conditioning. This new signal conditioning requires that the gain and balance point be calculated for every channel on each test. The formulas for these calculations depend on the sensor, the signal conditioning card used, and the test requirements. Due to the number and variety of machines tested at the Caterpillar Proving Grounds, these calculations needed to be automated. Using a few initial parameters and the information from our sensor calibration database, each channel’s balance point, gain, and expected slope are calculated. This system has increased productivity, accuracy, and consistency over manually calculating these parameters. This paper covers the sensor database, the calculated parameters and an overview of the way the system works.

      Rice, Michael; Friend, Daniel; Brigham Young University (International Foundation for Telemetering, 1997-10)
      This paper analyzes the bit error rates (BER) using data recorded during an F-16 test at Edwards Air Force Base in September, 1996. The effects of multipath fading on BER are presented. It is shown that significant increases in BER can occur when the received signal power remains at an acceptable level. Recordings of the received power spectrum during the test show that these BER increases are caused by frequency selective fades due to multipath interference. This paper illustrates that in these cases, significant data degradation can occur without drops in the received signal power.
    • Burst Analysis of Bit Errors on an F-16 Test Flight at Edwards AFB

      Rice, Michael; Welling, Kenneth; Landon, David; Brigham Young University (International Foundation for Telemetering, 1997-10)
      Bit errors induced by multipath interference occur in short bursts with relatively long intervals of error-free propagation. This paper analyzes the bursty nature of bit errors by examining synthetic error sequences generated from received voltage levels measured during low-altitude F-16 flights at Edwards AFB. The error gap distribution (which is a cumulative distribution function of the length of the error free intervals) and the block error probability are computed from the data. These parameters are useful in assessing the performance of error control coding strategies.
    • Common Airborne Processing System (CAPS) 2.0: Data Reduction Software on a Personal Computer (PC)

      Hunt, Trent W.; TYBRIN Corporation; Eglin Air Force Base (International Foundation for Telemetering, 1997-10)
      CAPS 2.0 provides a flexible, PC-based tool for meeting evolving data reduction and analysis requirements while supporting standardization of instrumentation data processing. CAPS 2.0 will accept a variety of data types including raw instrumentation, binary, ASCII, and Internet protocol message data and will output Engineering Unit data to files, static or dynamic plots, and Internet protocol message exchange. Additionally, CAPS 2.0 will input and output data in accordance with the Digital Data Standard. CAPS 2.0 will accept multiple input sources of PCM, MIL-STD-1553, or DDS data to create an output for every Output Product Description and Dictionary grouping specified for a particular Session. All of this functionality is performed on a PC within the framework of the Microsoft Windows 95/NT graphical user interface.

      James, Calvin L.; AlliedSignal Aerospace Inc. (International Foundation for Telemetering, 1997-10)
      The basic building blocks for implementing complex waveform generators using a look-up table approach are random access memory (RAM) and read only memory (ROM) devices. Due to technological advancements in field programmable gate array (FPGA) development, these devices have the ability to allocate large amounts of memory elements within the same structure. The self containment property makes the FPGA a suitable topology for complex waveform generation applications. In addition, this self containment property significantly reduces implementation costs by reducing the number of external components required to support many applications. This paper examines the use of FPGA’s in various complex waveform generation applications. In particular, a discussion will ensue examining possible mappings of the time domain response of the complex waveform into memory elements of the FPGA. The analyses and examples contained in the sequel are from existing waveform generation applications, developed for Gauissian Minimum Shift Keying (GMSK) and Unbalanced Quadriphase Shift Keying (UQPSK) modulation formats.

      Jones, Charles H.; Gardner, Lee S.; Edwards Air Force Base (International Foundation for Telemetering, 1997-10)
      How difficult is it to develop a pulse code modulation (PCM) stream data format? Specifically, given a size, in bits, and a set of parameter sample rates, how hard is it to find a mapping of the sample rates that fits into the frame size -- if one even exists? Using telemetry trees this paper will show that the number of possible mappings for a given set of parameters and sample rates grows exponentially in terms of the number of parameters. The problem can thus be stated in terms of finding a specific instance, or showing that no such instance exists, among an exponentially large number of potential mappings. Although not proof, this provides strong evidence that the PCM format design problem is NP-complete (meaning it is a member of nondeterministic polynomial space but not a member of deterministic polynomial space). That is, that the problem can not be solved in polynomial time and would take a computer years or centuries to solve relatively small instances of the problem. However, if the problem requirements are relaxed slightly, telemetry trees can be used to reduce the PCM formatting problem to linear time in terms of the number of parameters. This paper describes a technique that can provide an optimal and fully packed PCM format.

      Peart, David E.; Talbert, Jim; Lockheed Martin Vought Systems (International Foundation for Telemetering, 1997-10)
      In recent years we have seen an increase in the use of MIL-STD-1553 buses and other asynchronous data sources used in new missile and launcher designs. The application of multiplexed asynchronous buses in missiles and launchers is very common today. With increasing application of asynchronous data sources into very complex systems the need to acquire, analyze, and present one hundred percent of the bus traffic in real time or near real time has become especially important during testing and diagnostic operations. This paper discusses ways of converting asynchronous data, including MIL-STD-1553, into a telemetry format that is suitable for encryption, telemetering, recording, and presenting with Inter Range Instrumentation Group (IRIG) compatible off-the-shelf hardware. The importance of these designs is to provide the capability to conserve data bandwidth and to maximize the use of existing hardware. In addition, this paper will discuss a unique decode and time tagging design that conserves data storage when compared to the methods in IRIG Standard 106-96 and still maintains a very accurate time tag.

      Buckingham, Gary A.; Corey, Garth P.; U.S. Department of Energy; Sandia National Laboratories (International Foundation for Telemetering, 1997-10)
      The vast majority of all utility power quality problems consist of short duration surges, sags, and momentary power losses that wreak havoc among modern sensitive loads. To solve these power quality problems, a highly reliable, low-cost battery solution, the AC Battery PQ2000, developed with Department of Energy and Sandia National Laboratories assistance, is now available to eliminate these short duration power quality problems. Incorporated in this system is a communications interface which allows remote access over the telephone network using RS-232 protocol. The system is designed for standalone function without an operator present; however, because of the limited experience of utilities in the use of this type of battery energy storage system, capabilities have been incorporated to allow for datalogging and remote system control of the unit. This paper reviews power quality problems, outlines the system design philosophy from AC Battery Corporation, discusses the rationale for remote telemetering system design, and reviews the utility of this telemetry through the experience of a system installed in Georgia.

      Kibalo, Tom; Miles, Ben (International Foundation for Telemetering, 1997-10)
      Alliant Techsystems’ Advanced Technology Applications organization incorporates the latest IRIG standards for range equipment and operation. Over the past five years, our objective has been to assure interoperability among diverse data recording users while achieving technical excellence for our ADARIO(Analog Digital Adaptable Input Output) family of products. In this paper, we summarize 25 years of ADARIO development; technical challenges, risks and processes; as well as our five-year effort to modify and develop our recording system products to meet the evolutionary standards of technical excellence.