• A PARALLEL -SEQUENTIAL SEARCH ALGORITHM IN A HIGH DYNAMIC GPS RECEIVER

      Xingyu, Luo; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      It is need to design acquisition and tracking for code loop and carrier loop to detect the high dynamic Global Position System (GPS) signal. Acquiring signal quickly and shortening acquisition time in the cold case are key technology of a high dynamic GPS receiver. Moreover, fast acquisition of C/A code is the base of code tracking and carrier acquisition and tracking. This paper describes elements and implementation of a new parallel-sequential search Algorithm to acquire C/A code of the high dynamic GPS signal. And combined with a 12-channel correlator named GP2021 produced by GEC Co., the arithmetic implementation to acquire C/A code of the high dynamic GPS signal used sequential search based on DSP technology is also given.
    • Performance of a Bluetooth Based Structural Health Monitoring Telemetry Network

      Kosbar, Kurt; Uchil, Vilas; University of Missouri (International Foundation for Telemetering, 2002-10)
      The Bluetooth standard is intended to provide short-range (10-100 meter) wireless connectivity between mobile and desktop devices. It was developed as a replacement for short cables, and has the ability to form ad-hoc networks. A large inter-connection of piconets can be arranged to form a scatternet for data collection in a Bluetooth based structural health monitoring Telemetry network. The Bluetooth protocol architecture supports the formation of a daisy chain network. However Bluetooth technology was not intended for long daisy chain networks. In this work, we propose to evaluate the throughput and latency for data transmission in a long daisy chained Bluetooth based telemetry network.
    • PERFORMANCE STUDY OF ENHANCED FQPSK AND CONSTRAINED ENVELOPE MODULATION TECHNIQUES

      Borah, Deva K.; Horan, Stephen; New Mexico State University (International Foundation for Telemetering, 2002-10)
      This paper investigates the spectral properties and the bit error rate (BER) performance of enhanced FQPSK (EFQPSK) and constrained envelope modulation (CEM) techniques. Both the techniques are found to provide good spectral efficiencies. The EFQPSK signals are found to generate spectral lines for unbalanced data. An analytical spectral study for the spectral lines is presented. While the performance of CEM techniques has been presented in [6] for an ideal nonlinear amplifier, we present results for more realistic amplifiers with AM/AM and AM/PM effects. It is shown that such an amplifier generates spectral regrowth and a predistorter is required to reduce the adverse effects. A BER performance study with/without channel coding is also presented for the two techniques.
    • PHASE CENTER PROBLEMS WITH WRAP-AROUND ANTENNAS

      Meyer, Steven J.; Kujiraoka, Scott R.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      The Joint Advanced Missile Instrumentation (JAMI) program is integrating Global Positioning System (GPS) technology into missile telemetry systems. The weakest link appears to be the GPS antenna. The antenna on a missile is required to be flush mounted for aerodynamic reasons. Due to the missile’s tendency to roll, the antenna needs to be a multi-element omnidirectional antenna array. Therefore an antenna used on missiles is a wrap-around antenna since it will meet the flush mount and rolling requirements by giving omnidirectional coverage. JAMI has used readily available techniques for designing wrap-around telemetry antennas to develop a GPS wrap-around antenna and has discovered a major problem. The Phase Center of a wrap-around antenna tends to be a surface, not a point, and not necessarily at the centerline of the missile body. GPS measurements have been conducted to determine the Phase Center of the antenna. When the Phase Center is large, the GPS receiver perceives it as multipath and integer ambiguities cannot be resolved. This paper addresses the problems that have been uncovered and outlines the steps that are planned to resolve them.
    • PLASMA TELEMETRY IN HYPERSONIC FLIGHT

      Starkey, Ryan P.; Lewis, Mark J.; Jones, Charles H.; University of Maryland; Edwards Air Force Base (International Foundation for Telemetering, 2002-10)
      Problems associated with telemetry blackout caused by the plasma sheath surrounding a hypersonic vehicle are addressed. In particular, the critical nature of overcoming this limitation for test and evaluation purposes is detailed. Since the telemetry blackout causes great concern for atmospheric cruise vehicles, ballistic missiles, and reentry vehicles, there have been many proposed approaches to solving the problem. This paper overviews aerodynamic design methodologies, for which the required technologies are only now being realized, which may allow for uninterrupted transmission through a plasma sheath. The severity of the signal attenuation is dependent on vehicle configuration, trajectory, flightpath, and mission.
    • PROTOCOL LAYERING

      Grebe, David L.; Apogee Labs, Inc. (International Foundation for Telemetering, 2002-10)
      The advent of COTS based network-centric data systems brings a whole new vocabulary into the realm of instrumentation. The Communications and computer industries have developed networks to a high level and they continue to evolve. One of the basic techniques that has proven itself useful with this technology is the use of a “layered architecture.” This paper is an attempt to discuss the basic ideas behind this concept and to give some understanding of the vocabulary that has grown up with it.
    • PROTOTYPE DUAL-BAND TRANSMITTER FOR AERONAUTICAL TELEMETRY APPLICATIONS

      Jensen, Michael A.; Jones, Charles H.; Brigham Young University; Edwards Air Force Base (International Foundation for Telemetering, 2002-10)
      Recent changes in spectrum availability as well as higher demands for spectrum have motivated the development of telemetry transmit systems capable of fully operating over both L and S telemetry bands. However, enabling operation within these two bands poses new problems in system design. This paper presents a prototype system capable of operating between 1.4 and 2.4 GHz, which supports continuous phase modulation (CPM) waveforms such as pulse code modulation (PCM), frequency modulation (FM), and shaped offset quadrature phase shift keying (SOQPSK). The system architecture is detailed, and the prototype performance is discussed.
    • QAM Multi-path Characterization Due to Ocean Scattering

      Swanson, Richard; Dimsdle, Jeff; Petersen, Tom; Pasquale, Regina; Bracht, Roger; Honeywell Federal Manufacturing & Technologies; Los Alamos National Laboratory (International Foundation for Telemetering, 2002-10)
      A series of RF channel flight characterization tests were recently run to benchmark multi-path performance of high-speed quadrature amplitude modulation (QAM) over the ocean surface. The modulation format was differential-phase/absolute-amplitude two level polar 16 QAM. The bit rate was 100 Megabits per second with a symbol period of 40nS. An aircraft radiated the test signal at 5 different altitudes. It made two inward flights, on two different days, at each altitude with vertical and horizontal polarization, respectively. Receivers, using circular antenna polarization, were in two different locations. Analysis of the resulting data shows flat fading and frequency selective fading effects.
    • RECORDERS IN NETWORKED DATA ACQUISITION SYSTEMS

      Grebe, David L.; Apogee Labs Inc. (International Foundation for Telemetering, 2002-10)
      The role of recorders in telemetry applications has undergone many changes throughout the years. We’ve seen the evolution from multi-track tape to disk to solid state technologies, both for airborne and ground based equipment. Data acquisition and collection system design has changed as well and a recent trend in airborne is to merge acquisition and recording. On the ground, increased decentralization of data collection and processing has generated the requirement to provide backup storage to protect against communication circuit outages. This paper explores the trend to adopt network based data acquisition, collection, and distribution systems for telemetry applications and the impact on recording techniques and equipment. It shows that in this emerging approach the recorder returns to its root mission of attempting to provide the fastest, largest capacity for the least amount of investment. In a network based architecture the recorder need only accept and reproduce data operating independently from the acquisition process.
    • SIGNAL PROCESSING ABOUT A DISTRIBUTED DATA ACQUISITION SYSTEM

      Kolb, John; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      Because modern data acquisition systems use digital backplanes, it is logical for more and more data processing to be done in each Data Acquisition Unit (DAU) or even in each module. The processing related to an analog acquisition module typically takes the form of digital signal conditioning for range adjust, linearization and filtering. Some of the advantages of this are discussed in this paper. The next stage is powerful processing boards within DAUs for data reduction and third-party algorithm development. Once data is being written to and from powerful processing modules an obvious next step is networking and decom-less access to data. This paper discusses some of the issues related to these types of processing.
    • SOFTWARE RADIO TECHNOLOGY AND CHALLENGES

      Chapin, John; Shah, Alok; Vanu, Inc. (International Foundation for Telemetering, 2002-10)
      This paper provides an overview of software radio and its current state in the industry. Software radio is a technology in which all of the waveform processing, including the physical layer, of a wireless device moves into software. If designed properly, this approach leads to dramatically improved device flexibility, software portability, and reduced development costs. Of course, such a technology brings with it numerous challenges, from hardware components to power constraints to the regulatory environment.
    • SPACE COMMUNICATION DEMONSTRATION USING INTERNET TECHNOLOGY

      Israel, Dave; Parise, Ron; Hogie, Keith; Criscuolo, Ed; National Aeronautics and Space Administration; Computer Sciences Corp (International Foundation for Telemetering, 2002-10)
      This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of Internet communication technologies to space communication. The goal is to provide global addressability and standard network protocols and applications for future space missions. It describes the communication architecture and operations concepts that will be deployed and tested on a Space Shuttle flight in July 2002. This is a NASA Hitchhiker mission called Communication and Navigation Demonstration On Shuttle (CANDOS). The mission will be using a small programmable transceiver mounted in the Shuttle bay that can communicate through NASA’s ground tracking stations as well as NASA’s space relay satellite system. The transceiver includes a processor running the Linux operating system and a standard synchronous serial interface that supports the High-level Data Link Control (HDLC) framing protocol. One of the main goals will be to test the operation of the Mobile IP protocol (RFC 2002) for automatic routing of data as the Shuttle passes from one contact to another. Other protocols to be utilized onboard CANDOS include secure login (SSH), UDP-based reliable file transfer (MDP), and blind commanding using UDP. The paper describes how each of these standard protocols available in the Linux operating system can be used to support communication with a space vehicle. It will discuss how each protocol is suited to support the range of special communication needs of space missions.
    • SPACE-TIME CODING FOR WIRELESS COMMUNICATIONS

      Jensen, Michael A.; Rice, Michael D.; Brigham Young University (International Foundation for Telemetering, 2002-10)
      Signal fading and intersymbol interference created by multipath propagation have traditionally limited the throughput on wireless communications systems. However, recent research has demonstrated that by using multiple antennas on both transmit and receive ends of the link, the multipath channel can actually be exploited to achieve increased communication throughput over single-antenna systems. This paper provides an introductory description of such multi-antenna communications systems, focusing on basic explanations of how they achieve capacity gains. Computed and measured capacity results are used to demonstrate the potential of these systems.
    • SPECIFYING A PCMCIA IRIG-106 (Ch. 4) DECOMMUTATOR

      Mc Girr, Niall; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      There are many applications where an ultra-compact PC (palm-top) is required for quick analysis of PCM data. There are many design issues associated with the design of a PC-Card (PCMCIA) decommutator. • Is it possible to connect a 20Mbps PCM stream? • What outputs are required from such a card? • How many cards can be used? • Which mode to use (memory or I/O) • How to program such a card • How to develop third-party software for analysis of data This paper discusses some of these issues and the applications for such a card.
    • SPECTRAL EFFICIENCY OF 8-ARY PSK MODULATION UTILIZING SQUARE ROOT RAISED COSINE FILTERING

      Scheidt, Kelly J.; CMC Electronics Cincinnati (International Foundation for Telemetering, 2002-10)
      As frequency allocation restrictions are tightening, and data rates are increasing, it is becoming necessary to incorporate higher order modulation techniques to make more efficient use of available spectrum. When used with Square Root Raised Cosine filtering, 8-ary Phase Shift Keyed modulation is a spectrally efficient technique that makes better use of today’s RF spectrum in comparison to standard formats. This paper will discuss 8-ary PSK modulation and its spectral efficiency with a SRRC filter, along with comparisons to BPSK, QPSK, and FSK.
    • SPECTRAL EFFICIENCY/BIT ERROR RATE OF FQPSK AND OTHER NON-COHERENT SYSTEMS SUPERIOR TO COHERENT SYSTEMS FOR SMS AND BURSTED TDMA AND CDMA SYSTEMS

      McCorduck, James A.; Feher, Kamilo; MatrixSat, Inc.; University of California; Digcom, Inc. (International Foundation for Telemetering, 2002-10)
      For faster acquisition in bursted environments for SMS (Short Messaging Service) and other lower-bit rate applications, non-coherent detection techniques are proposed. Non-Coherent detection demodulators are proposed because faster acquisition capability in bursted environments can result in a reduced amount of preamble bits in the messaging frame, i.e. less overhead, resulting in an effective increase in spectral efficiency. Reducing the preamble can also provide performance enhancement opportunities for Feher Quadrature Phase Shift Keying (FQPSK) [1] and for other systems. The preamble can also be varied to provide for better Bit Error Rate (BER) performance. The lower bit rate environment also gives the opportunity to employ simpler architectures in lieu of preamble modification. Several non-coherent detection alternatives are described.
    • A STANDARD LINK-LAYER PROTOCOL FOR SPACE MISSION COMMUNICATIONS

      Parise, Ron; Hogie, Keith; Criscuolo, Ed; Schnurr, Rick; Wesdock, John; Burns, Mark; Computer Sciences Corp; NASA; ITT Industries (International Foundation for Telemetering, 2002-10)
      A necessary step for using Internet Protocols in space is to establish the basic link-layer framing protocol for delivering Internet datagrams over satellite RF links. This paper discusses the low-level data link issues related to using the ISO standard High-level Data Link Control (HDLC) protocol to support spacecraft communications. A major driver for using HDLC is its very wide usage in the Internet today and the large amount of commercially available network equipment and test equipment. The results of a high-fidelity link simulation using HDLC are presented along with results of tests performed in 2000-2001 using Internet protocols over HDLC on the UoSAT-12 spacecraft. A rationale is provided for the selection of HDLC/Frame-Relay framing along with the IETF multi-protocol encapsulation. It also discusses the historical usage of HDLC on over 70 satellite missions. The paper also describes how HDLC relates to various applications of forward-error-correction (FEC) coding techniques, such as convolutional coding and Reed-Solomon. It describes approaches for using these techniques in ways that are independent of the protocols used at the data link layer and above. It covers issues primarily related to layer 2 (Data Link) and its relationship to layer 1 (Physical). It does not cover layer 3 (Network) and above.
    • A STATUS REPORT OF THE JOINT ADVANCED MISSILE INSTRUMENTATION PROJECT HIGH DYNAMIC GPS- WE FINALLY GOT IT

      Powell, Dave; Scofield, Don; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      Joint Advanced Missile Instrumentation (JAMI), a Central Test and Evaluation Investment Program (CTEIP) initiative, is developing advanced telemetry system components that can be used in an integrated instrumentation package for tri-service small missile test and training applications. JAMI demonstrated significant improvement in the performance of low-cost Global Positioning System (GPS) based Time-Space-Position Information (TSPI) tracking hardware that can be used for world-wide test and training. Acquisition times of less than 3 seconds from a cold start and tracking dynamics to over 60 Gs were demonstrated. The design of a programmable Flight Termination Safe and Arm device has been completed. This paper discusses the progress of the program during the past year and the efforts planned for fiscal year 2002. High dynamic testing results of GPS and Inertial measurement Unit (IMU) devices and problems encountered are discussed.
    • THE STUDY OF EMBEDDED INTELLIGENT VEHICLE NAVIGATION SYSTEM*

      Shengxi, Ding; Bo, Zhang; Jingchang, Tan; Dayi, Zeng; Beijing University of Aeronautics and Astronautics; Chongqing Bashan Instrumental Factory (International Foundation for Telemetering, 2002-10)
      The intelligent vehicle navigation system is the multifunctional and complex integrate system that involved in auto positioning technology, geography information system and digital map database, computer technology, multimedia and wireless communication technology. In this paper, the autonomous navigation system based on the embedded hardware and embedded software platform is proposed. The system has advantages of low cost, low power consumption, multifunction and high stability and reliability.
    • THE SYSTEM DESIGN OF DIGITAL TWELVE-CHANNEL GPS SIMULATOR

      Juan, Lu; Qing, Chang; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      With the purpose of testing the performance of GPS receivers, a GPS signal simulator is needed that can emulate the real GPS signals under all kinds of the conditions. This paper analyzes the single channel and multi-channel GPS signals’ characters in time domain and frequency domain, and discusses a mathematic model of the twelve-channel GPS simulator. In order to reduce the difficulties of the hardware design, this model is designed to provide the IF signal directly by applying the idea of “software radio”and the theory of interpolation. Simulation results with SystemView software demonstrate the feasibility of the system scheme. A practical hardware design of this system is described.