• ENHANCED FLIGHT TERMINATION SYSTEM PROGRAM - PART TWO

      McAndrews, Thomas J., III; TYBRIN Corporation (International Foundation for Telemetering, 2002-10)
      The Air Force Flight Test Center in association with the Range Commanders Council (RCC) Range Safety Group is conducting a program that will explore the next generation of ground-based flight termination technology, known as the Enhanced Flight Termination System (EFTS) program. The first part of the program was successfully concluded in May 2002. The Government is leading this program with support from contractors, academia, and other RCC groups including the Telemetry Group, Frequency Management Group, and Telecommunications and Timing Group. Additionally, the National Security Agency is providing key support along with vendors who design, build and test range safety systems. This paper will discuss details of the design validation and development phases (part two) of the EFTS program. Redesign of flight termination receivers and ground system modification plans will be discussed as well as flight and ground hardware testing objectives.
    • LOW BUDGET APPROACH TO ACCURATE TIME TAGGING OF SATELLITE DATA

      Fike, Brian O’dell; Weiss, Michael A.; Ball Aerospace & Technologies Corp. (International Foundation for Telemetering, 2002-10)
      The GEOSAT Follow-On (GFO) Time Tag Correlation System (TTCS) was implemented as a ground-based time correlation system for precision time tagging of satellite data. This system uses simple ground hardware and software to convert satellite time to UTC, resulting in time tagging of payload data to within +/- 20 microseconds. The technique described in this paper eliminates the need for an on-board satellite Ultra-Stable Oscillator (USO) to achieve precision time tagging of satellite data and, therefore, can result in a significant cost savings to future missions.
    • 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.
    • 3-D Ray-Tracing Simulations for 5.7GHz RF Indoor Position Location System

      Kosbar, Kurt; Annamraju, Venu; Burns, Thomas; University of Missouri-Rolla (International Foundation for Telemetering, 2002-10)
      The objective of the project is to continuously track a handheld device in an office, with centimeter accuracy in the three dimensions. A 3-D ray-tracing algorithm has been developed to simulate the impulse response of the indoor channel. The algorithm can evaluate the impulse response at multiple receiver locations. Non-linear optimization has been used to eliminate the need for multiple runs of simulation. The optimization program also significantly reduces the number of rays launched. The algorithm incorporates bandwidth effects on multipath resolution of the system.
    • FLIGHT SAFETY SYSTEM FOR UNMANNED AIRBORNE VEHICLES (UAVs)

      Pérez-Falcón, Tony; Kolar, Ray; Reliable System Services Corporation; Atlantic Coast Technologies, Inc. (International Foundation for Telemetering, 2002-10)
      This paper presents a Flight Safety System (FSS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of flying Over-the-Horizon (OTH) and outside test range airspace. Expanded uses beyond flight safety, such as UAV Air Traffic Control, are considered also. This system satisfies the operational requirement for a Hazard Control Communication Channel as well as providing a reverse communications channel to provide Safety Critical Information to the Range Safety Officer (RSO). Upon examining 60 communications candidates, IRIDIUM accessed through a Data Distribution Network (DDN), with ARINC being a potential service provider, is recommended.
    • ENCRYPTED BIT ERROR RATE TESTING

      Guadiana, Juan M.; Macias, Fil; Naval Surface Warfare Center; White Sands Missile Range (International Foundation for Telemetering, 2002-10)
      End-to-End testing is a tool for verifying that Range Telemetry (TM) System Equipment will deliver satisfactory performance throughout a planned flight test. A thorough test verifies system thresholds while gauging projected mission loading all in the presence of expected interference. At the White Sands Missile Range (WSMR) in New Mexico, system tests are routinely conducted by Range telemetry Engineers and technicians in the interest of ensuring highly reliable telemetry acquisition. Even so, flight or integration tests are occasionally halted, unable to complete these telemetry checks. The Navy Standard Missile Program Office and the White Sands Missile Range, have proactively conducted investigations to identify and eliminate problems. A background discussion is provided on the serious problems with the launcher acquisition, which were resolved along the way laying the ground work for effective system testing. Since there were no provisions to test with the decryption equipment an assumption must be made. Encryption is operationally transparent and reliable. Encryption has wide application, and for that reason the above assumption must be made with confidence. A comprehensive mission day encrypted systems test is proposed. Those involved with encrypted telemetry systems, and those experiencing seemingly unexplainable data degradations and other problems with or without encryption should review this information.
    • EQUIPMENT TIME-DELAY (ETD) MEASUREMENT TECHNOLOGY FOR CONTINUOUS WAVE TRANSPONDER

      Chengfang, Huang; Jianping, Hu; Southwest Institute of Electronics Technology (International Foundation for Telemetering, 2002-10)
      The Equipment Time-Delay (ETD) measurement technology for Continuous Wave (CW) transponder is discussed with emphasis on the principle of measuring the ETD of the intermediate frequency (IF) modulation transponder through measuring subcarrier modulation sideband tone phase. A general method for measuring ETD of different types of transponder (including IF-modulation transponder) is introduced. Finally the measurement method error is analyzed.
    • 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.
    • EXTENDING THE RANGE OF PCM/FM USING A MULTISYMBOL DETECTOR AND TURBO CODING

      Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      It has been shown that a multi-symbol detector can improve the detection efficiency of PCM/FM by 3 dB when compared to traditional methods without any change to the transmitted waveform. Although this is a significant breakthrough, further improvements are possible with the addition of Forward Error Correction (FEC). Systematic redundancy can be added by encoding the source data prior to the modulation process, thereby allowing channel errors to be corrected using a decoding circuit. Better detection efficiency translates into additional link margin that can be used to extend the operating range, support higher data throughput, or significantly improve the quality of the received data. This paper investigates the detection efficiency that can be achieved using a multisymbol detector and turbo product coding. The results show that this combination can improve the detection performance by nearly 9 dB relative to conventional PCM/FM systems. The increase in link margin is gained at the expense of a small increase in bandwidth and the additional complexity of the encoding and decoding circuitry.
    • FQPSK-B Baseband Filter Alternatives

      Jefferis, Robert; TYBRIN Corporation (International Foundation for Telemetering, 2002-10)
      Designers of small airborne FQPSK-B (-B) transmitters face at least two significant challenges. First, many U.S. Department of Defense (DOD) test applications require that transmitters accommodate a continuum of data rates from 1, to at least 20 Mb/s in one design. Another challenge stems from the need to package a high-speed digital baseband signal generator in very close proximity to radio frequency (RF) circuitry required for 1.4 to 2.4 GHz operation. The -B baseband filter options prescribed by Digcom/Feher [2] are a major contributor to variable data rate design challenges. This paper summarizes a study of -B filter alternatives and introduces FQPSK-JR (JR), an alternative to -B that can simplify digital baseband transmitter designs. Very short impulse response digital filters are used to produce essentially the same spectral efficiency and nonlinear amplifier (NLA) compatibility as -B while preserving or improving detection efficiency (DE). In addition, a strategy for eliminating baseband shaping filters is briefly discussed. New signaling wavelets and, modified wavelet versus symbol sequence mapping rules associated with them, can be captured from a wide range of alternative filter designs.
    • 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.
    • Making All The Data Available Some Of The Time In Very Large Telemetry Volume Space Applications

      Cook, David B. (International Foundation for Telemetering, 2002-10)
      What do you do when your downlink telemetry needs outstrip your downlink bandwidth capability? The telemetry needed to support construction and operation of the largest, most complex engineering project ever undertaken, the International Space Station (ISS), already requires utilization of the full capacity of the downlink S-band capacity, yet there are additional systems and capabilities still to be added by NASA and the International Partners. The ISS Command and Telemetry Team has developed a method of swapping packets of telemetry that are intended for special operations, while simultaneously sending essential systems telemetry and less critical telemetry that is needed on a continuous basis. To support this attempt to “make available all of the data at least some of the time” the team developed concepts for grouping telemetry into families that would always be selected as a group and then created a set of metadata associated with these groups. This metadata is pre-defined to support automated selection and scrubbing of telemetry to correspond to major upgrades in the command and control software for the ISS. The new process will at least double the effective S-band downlink bandwidth. It will also provide automated selection, scrubbing, reporting and verification of telemetry selections.
    • Hardware Description for the Advanced Subminiature Telemetry System

      Sadowski, Eric M.; Schmidt, Robert; Cleveland Medical Devices Inc. (International Foundation for Telemetering, 2002-10)
      The Advanced Subminiature Telemetry System (ASMT) contract was awarded several years ago and the basic framework for the overall system has been described in earlier papers. This paper discusses an overview of the design of the hardware pieces to create the ASMT system.
    • LOW-COST TELEMETRY USING FREQUENCY HOPPING AND THE TRF6900™ TRANSCEIVER1

      Thornér, Carl-Einar I.; Iltis, Ronald A.; University of California, Santa Barbara (International Foundation for Telemetering, 2002-10)
      The ISM bands have opened up new opportunities for telemetry using spread-spectrum communications. A low-cost frequency-hopping radio is described here for the 900 MHz ISM band that can be programmed with a wide range of hop and data rates. The ‘C6201 DSP from TI is used to control the frequency and data rate of the TI TRF6900 transceiver chip using a custom interface of the 6201 EVM board to the serial I/O on the 6900 evaluation board.
    • 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.
    • BANDWIDTH AND POWER EFFICIENCY TRADE-OFFS OF SOQPSK

      Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      Shaped Offset QPSK (SOQPSK), as proposed and analyzed by Terrance Hill, is a family of constant envelope waveforms that is non-proprietary and exhibits excellent spectral containment and detection efficiency. Results for two variants, defined as SOQPSK-A and -B, have previously been presented. However, it remains to be seen whether or not even more attractive choices exist. This paper explores the bandwidth and power efficiency trade-offs of the entire SOQPSK family using computer simulations and analytical performance bounds.
    • THE VEHICLE MONITORING SYSTEM BASED ON GPRS

      Xu, Liu; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      The Vehicle Monitoring System based on GPRS is a system using GPRS network to transmit data, including location data, time data and so on .It has many advantages compared with those systems based on other communication modes. The key of the system lies in how to build up the connection with exterior data network. In this paper, the constitution of the system is introduced, and the course of building up connection with exterior data network is described in detail.
    • EMBEDDED GIS IN INTELLIGENT NAVIGATION SYSTEM

      Xiaobo, Xie; Qishan, Zhang; Xingjian, Huang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      Embedded GIS in Intelligent Navigation System is a special information system. This paper puts forward several basic principles and constraints during design for Embedded GIS at first, and then analyzes the feature of embedded platform and the function of Intelligent Navigation System, and presents a realization scheme of Embedded GIS.
    • CHAOTIC SPREAD-SPECTRUM SEQUENCE GENERATED BY MULTILEVEL QUANTIFYING AND THEIR PROPERTIES

      Chengquan, Au; Tingxian, Zhou; Harbin Institute of Technology (International Foundation for Telemetering, 2002-10)
      According to the advantages of chaotic analog sequences and chaotic binary sequences, this paper proposes a method generating chaotic binary spread-spectrum sequence by multilevel quantifying. This paper proved that even correlation and odd correlation between such sequences of length N are all Gaussian distributed with mean 0 and variance N, the even of mean-square cross-correlation is N, and the variance of mean-square cross-correlation is 2N. The method can increase the number of chaotic sequences, made the spread-spectrum system more secure. The theoretical analyses and the results of simulation show that the performance of such sequence general is as same as traditional spread-spectrum sequence, its number is very large, and can be used in CDMA in future.
    • 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.