• DOPPLER SHIFTED SPREAD SPECTRUM CARRIER RECOVERY USING REAL-TIME DSP TECHNIQUES

      De Leon, Phillip L.; Scaife, Bradley J.; New Mexico State University (International Foundation for Telemetering, 1998-10)
      In any satellite communication, the Doppler shift associated with the satellite’s position and velocity must be calculated in order to determine the carrier frequency. If the satellite state vector is unknown then some estimate must be formed of the Doppler-shifted carrier frequency. One elementary technique is to examine the signal spectrum and base the estimate on the dominant spectral component. If, however, the carrier is spread (as in most satellite communications) this technique may fail unless the chip rate-to-data rate ratio (processing gain) associated with the carrier is small. In this case, there may be enough spectral energy to allow peak detection against a noise background. In this paper, we present a method to estimate the frequency (without knowledge of the Doppler shift) of a spread-spectrum carrier assuming a small processing gain and binary-phase shift keying (BPSK) modulation. Our method relies on a simple, averaged discrete Fourier transform along with peak detection. We provide simulation results indicating the accuracy of this method. In addition, we will describe an all-digital hardware design based around a Motorola DSP56303 and high-speed A/D which implements this technique in real-time. The hardware design is to be used in NMSU’s implementation of NASA’s demand assignment, multiple access (DAMA) service.
    • DESIGN AND PERFORMANCE OF A MULTI-MODE RECEIVER CARD

      O’Cull, Douglas C.; Microdyne Communications Technologies, Inc. (International Foundation for Telemetering, 1998-10)
      This paper will discuss the design and performance of a multi-mode receiver. The receiver is designed to operate in standard VME and PC environments and will support data rates up to 20 Mbps. The paper will discuss new digital demodulation techniques that support PCM-FM, PCM-PM, FM, PM, BPSK, QPSK and O-QPSK modulation. This new demodulator also includes a built in bit sync with soft decision outputs. This paper will provide an overview on digital filtering used in the second IF filter which provides dynamic changing of the IF bandwidth.
    • MINIATURE PENETRATOR (MINPEN) ACCELERATION RECORDER DEVELOPMENT AND TEST

      Franco, R. J.; Platzbecker, M. R.; Sandia National Laboratories (International Foundation for Telemetering, 1998-10)
      The Telemetry Technology Development Department at Sandia National Laboratories actively develops and tests acceleration recorders for penetrating weapons. This new acceleration recorder (MinPen) utilizes a microprocessor-based architecture for operational flexibility while maintaining electronics and packaging techniques developed over years of penetrator testing. MinPen has been demonstrated to function in shock environments up to 20,000 Gs. The MinPen instrumentation development has resulted in a rugged, versatile, miniature acceleration recorder and is a valuable tool for penetrator testing in a wide range of applications.
    • REAL-TIME INTEGRATION OF RADAR INFORMATION, AND GROUND AND RADIOSONDE METEOROLOGY WITH FLIGHT RESEARCH DATA

      Billings, Don; Wei, Mei; Leung, Joseph; Aoyagi, Michio; Shigemoto, Fred; Honeyman, Rob; NASA; Recom Technologies (International Foundation for Telemetering, 1998-10)
      Although PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.
    • LASER BASED TECHNIQUE TO EVALUATE DGPS BASED CAT III LANDING SYSTEMS

      Shigemoto, Fred; Wei, Mei; Somes, Austin; Ng, Sunny; NASA; Sterling Software (International Foundation for Telemetering, 1998-10)
      FAA is currently evaluating DGPS based CAT III Landing Systems for use as the next generation commercial aviation landing system standard. Any technique to validate such a DGPS based system must have at least equivalent accuracy. A laser position tracking system coupled with a high performance real-time computational capability was developed providing real-time analysis of performance. This real-time performance measurement system was key in enabling the quick completion of a large number of test approach and landings needed to achieve statistically accurate results.
    • A NEW GENERATION OF RECORDING TECHNOLOGY THE SOLID STATE RECORDER

      Jensen, Peter; Thacker, Christopher; Merlin Engineering Works (International Foundation for Telemetering, 1998-10)
      The Test & Evaluation community is starting to migrate toward solid state recording. This paper outlines some of the important areas that are new to solid state recording as well as examining some of the issues involved in moving to a direct recording methodology. Some of the parameters used to choose a solid state memory architecture are included. A matrix to compare various methods of data recording, such as solid state and magnetic tape recording, will be discussed. These various methods will be evaluated using the following parameters: Ruggedness (Shock, Vibration, Temperature), Capacity, and Reliability (Error Correction). A short discussion of data formats with an emphasis on efficiency and usability is included.
    • A NEW GENERATION OF DATA RECORDERS BASED ON DLT TECHNOLOGY

      Thames, Fred; Avalon Electronics Ltd (International Foundation for Telemetering, 1998-10)
      As the performance of inexpensive commercial off-the-shelf (COTS) data storage devices continues to increase, the temptation to use them as the basis for data capture products for military and industrial applications becomes ever more compelling. For example, the Digital Linear Tape (DLT) format now offers a 270 Gigabits per cassette capacity at a sustained transfer rate of 40 Mbits/s – performance which would have cost tens or even hundreds of thousands of dollars per system just a few years ago. But to transplant such a device from its benign office habitat into a data capture product which will function reliably and consistently in a wide range of field and platform environments is an engineering task fully as difficult and complex as designing an environmentally robust recorder from scratch. This paper discusses the problems which typically have to be overcome; environmental protection, reliability, data integrity, power supplies, software issues, control and data interfacing, etc., citing practical examples of analog and digital DLT-based data recorders which are now entering service for telemetry, intelligence gathering, anti-submarine warfare and related applications
    • A C-BAND MOBILE TELEMETRY SYSTEM

      Wei, Zeng; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1998-10)
      In this paper, it is introduced that a C-Band mobile telemetry system designed for the satellite telemetry task. It can provide a wide range of bit rate and different code type and frame format which is completely set up by user in advance, to meet the requirements needs in different satellites. The PCM-PSK-PM signal and the PPM-MFSK-PM signal can be received and demodulated at the same time. Single channel monopulse technique is employed for automatic tracking. Angle calibration and angle tracking are performed in this system. Real-time data processing, displaying, testing of bit error rate and post-flight analyses is performed by PC type computer. All key components of the system may be programmed.
    • BANDWIDTH DRIVEN TELEMETRY

      Jones, Charles H.; Gardner, Lee S.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      “The radio frequency spectrum is a limited natural resource; therefore, efficient use of available spectrum is mandatory.” IRIG Standard 106-96 [4] As the availability of the frequency spectrum decreases and demands for bandwidth from users increases, the telemetry community will have to find ways to use spectrum efficiently. This paper is an overview of the major areas of research that promise potential increases in the efficient use of the telemetry spectrum. The discussion is summarized in a matrix that compares potential gains with overall costs for each research area using relative values of high, medium, and low.
    • QUALIFYING THE COCKPIT VOICE RECORDER AS AN INSTRUMENTATION RECORDER AND AIRCRAFT STRUCTURAL MONITORING INSTRUMENT

      Rohre, Stuart M.; The University of Texas at Austin (International Foundation for Telemetering, 1998-10)
      A novel concept using the cockpit voice recorder (CVR) as a structural vibration recording device, to aid in structural health monitoring of commercial and military aircraft, is outlined. The unused cables in the CVR wiring harness act as “latent transducers” that respond to structural vibrations, generating vibration signals, which the CVR records. Postprocessing of such data can provide clues to problem areas or changes in the signature of the aircraft. The standards which the CVR must meet to qualify as a instrumentation-quality recorder are discussed and the steps required to assure compliance are outlined.
    • WIDE-BAND RADIO FREQUENCY (RF) SOURCE SURVEILLANCE

      Gurr, J. Richard; Auvil, Anthony; Rizzo, Jim; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Reduction in available radio frequency (RF) spectrum for use in aircraft testing has steadily increased the probability of interference. The increase in users and required bandwidth generates requirements for increased monitoring and active management of the RF spectrum. The detection of background RF emissions and monitoring of authorized users will be used by future range test engineers to make decisions on when and where to conduct test missions to minimize the probability of interference. The detection of authorized users exceeding their allotted RF spectrum as well as unknown emitters should include: the general geographic area of potential interference, and times of transmission. This paper outlines the development of a complete system for wide-band RF monitoring to identify and locate active emissions. The RF surveillance system proposed must be inexpensive, easy to maintain, support large area coverage, and monitor wide bandwidths at long range. The system should contain software for emitter identification, which will determine where the current background and authorized RF transmissions occur and how they might effect authorized transmissions, and specialized software to alert spectrum managers of potential interference scenarios in real time based upon the daily schedule.
    • AN EFFICIENCY STUDY OF TELEMETRY DATA CYCLE MAPS

      Jones, Charles H.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Data cycle maps (DCM) describe the cyclic mapping of telemetered data. The efficiency of a DCM thus directly effects the efficiency of the use of the telemetry spectrum. The availability of this spectrum is decreasing while the demand is increasing. Certainly one of the first things to be done in trying to alleviate this bandwidth crunch is to make sure that all bits in a telemetry stream are useful and required. This paper provides results of a study on what types of bits there are in a DCM and how the bits were allocated in DCMs actually used at Edwards AFB, California.
    • FQPSK Doubles Spectral Efficiency of Telemetry: Advances and Initial Air to Ground Flight Tests

      Feher, Kamilo; Digcom, Inc.; University of California (International Foundation for Telemetering, 1998-10)
      FQPSK is the abbreviation for Feher Quadrature Phase Shift Keying (FQPSK) patented systems [1]. Digcom, Inc. licensed FQPSK products demonstrated significant spectral saving and RF power efficient robust BER performance advantages. These bit rate agile modems and Non Linearly Amplified (NLA) transceivers, DSP and hardware implementations, and in some instances “software-radios” (20kb/s to more than 100Mb/s) and RF frequency agile (from 150MHz to more than 40GHz) developments and systems have recently been demonstrated and deployed. The spectral efficiency, i.e., data throughput capability of the 1st generation of FQPSK, as demonstrated in initial Advanced Range Telemetry (ARTM) flight tests, approximately doubles while 2nd generation “FQPSK-2” systems have the potential to quadruple the spectral efficiency of operational PCM/FM telemetry systems and be backward compatible with the 1st generation of FQPSK technologies. It is also demonstrated that the spectral efficiency advantage of FQPSK over that of NLA power efficient GMSK, OQPSK and QPSK modulated transceivers is in the 50% to 300% range and that the potential spectral efficiency advantage of FQPSK-2 over GMSK [1] is in the 200% to 500% range. Based on extensive multi-year studies of alternative solutions for spectral and RF power efficient, robust BER performance systems, several commercial US and international organizations, AIAA, CCSDS, NASA, ESA, CCSDS and various programs of the US Department of Defense (DoD) concluded that FQPSK offers the most spectrally efficient high performance-high speed proven technology solutions and recommended FQPSK standardization for several data links. Initial DoD-ARTM Program Office Air-to-Ground L-band and S-band jet airborne telemetry Test and Evaluation (T&E) data, obtained during the summer of 1998 are briefly highlighted. These include simultaneosly tested FQPSK and PCM/FM. In these tests the following ARTM objectives have been demonstrated: (a) FQPSK approximately doubles the spectral efficiency of currently operational PCM/FM; (b) The Data Link Performance of these two systems is comparable. The American Institute of Aeronautics and Astronautics (AIAA) draft modulation standard recommended to the DoD, NASA and CCSDS, was approved by the AIAA [23]. The AIAA standard recommends “that FQPSK modulation be immediately adopted as the interim increment–1 standard.”
    • ELIMINATION OF SIDELOBE RESPONSE

      Herold, F. W.; Kaiser, J. A.; Fredrick Herold & Associates, Inc. (International Foundation for Telemetering, 1998-10)
      Conventional phased arrays nominally sum the signals received by the elements prior to detection. By multiplying rather than summing signals received from pairs of elements, i.e., interferometer pairs, a set of Spatial Frequencies (SFs) is obtained. Obtaining the SFs requires employment of a multiple local oscillator technique. When summed, these spatial frequencies produce a single lobed (voltage) radiation pattern which, when passed through a biased detector, removes all sidelobes from the response at a small loss of desired signal power.
    • NEXT GENERATION DIGITAL BEAMFORMING ARRAY OPTIMIZED BY NEURAL NETWORK BEAMFORMING TECHNIQUES

      Sullivan, Arthur; Christodoulou, Christos; Chandler, Charles W. (International Foundation for Telemetering, 1998-10)
      The next generation Digital Beamforming Array (DBFA) requires techniques beyond the existing adaptive processing and optimization approaches. By utilizing neural network processing and genetic algorithms that mimic complicated natural processes, such as the brain and natural selection, new and superior Antenna Arrays can be designed. The use of Neural Networks and Genetic Algorithms combined with the existing techniques for DBFAs can yield the ultimate in “real-time,” “smart” antenna performance. Cost is significantly reduced by; allowing large manufacturing tolerances, the use of inexpensive components, and correcting by neural network techniques. This paper describes the technology and proposes a practical application of the technique to design a DBFA to track and transmit/receive telemetry from a shipboard vertically launched medium range missile.
    • FQPSK-O: An Improved Performance Constant Envelope Modulation Scheme for OQPSK

      Lee, Tong-Fu; Wang, Shih-Ho; Liu, Chia-Liang; University of California; Industrial Technology Research Institute (International Foundation for Telemetering, 1998-10)
      A new constant envelope modulation scheme for OQPSK, called FQPSK-O, is presented. This modulation technique is an extension of the Feher Quadrature Shift Keying (FQPSK) patented technologies, see Ref[l]. This scheme uses cubic spline interpolation to generate very smooth baseband waveforms in order to increase the spectral and power efficiency. Being a constant envelope modulation, FQPSK-O can operate with class C power amplifier without spectrum regrowth. We achieve a more compact spectrum with comparable bit error rate performance. For example, the spectrum of FQPSK-O is 25% narrower than that of GMSK with BT(b)=0.3 and FQPSK-1 with hardlimiter [2] at -40 dB attenuation point. For coherent demodulation under AWGN channel, FQPSK-O has almost the same BER performance as FQPSK-1 with hardlimiter. Both of them are better than GMSK with BT(b)=0.3 for BER < 10^-4. In Rayleigh fading channel, FQPSK-O outperforms GMSK with BT(b)=0.3 by 2 dB. FQPSK-O is an excellent scheme for wireless and satellite communications which require high spectral and power efficiency.
    • SIGNAL GENERATOR AIDS ACQUISITION OF LOW EARTH ORBIT SATELLITES

      O’Cull, Douglas; Microdyne Corporation (International Foundation for Telemetering, 1998-10)
      This paper discusses modifications made to a commercial-off-the-shelf (COTS) signal generator that aids acquisition of low earth orbit (LEO) satellites. The modification compensates for the Doppler Frequency offset that commonly affects acquisition of LEO satellites. This allows the user to use a COTS signal generator for the uplink exciter. User programmable features have been added to the signal generator, which compensates for the Doppler Shift.
    • A MOBILE RANGE SYSTEM TO TRACK TELEMETRY FROM A HIGH-SPEED INSTRUMENTATION PACKAGE

      Leung, Joseph; Aoyagi, Michio; Billings, Donald; Hoy, Herbert; Lin, Mei; Shigemoto, Fred; NASA (International Foundation for Telemetering, 1998-10)
      As renewal interest in building vehicles based on hypersonic technologies begin to emerge again, test ranges anticipating in supporting flight research of these vehicles will face a set of engineering problems. Most fundamentals of these will be to track and gather error free telemetry from the vehicles in flight. The first series of vehicles will likely be reduced-scale models that restrict the locations and geometric shapes of the telemetry antennas. High kinetic heating will further limit antenna design and construction. Consequently, antennas radiation patterns will be sub-optimal, showing lower gains and detrimental nulls. A mobile system designed to address the technical issues above will be described. The use of antenna arrays, spatial diversity and a hybrid tracking system using optical and electronic techniques to obtain error free telemetry in the present of multipath will be presented. System tests results will also be presented.
    • THE DESIGN AND CONSTRUCTION OF A C-BAND RAIL-SAR AND AN S-BAND DOPPLER RADAR

      Crockett, Donald E.; Arnold, David V.; Jensen, Michael A.; Brigham Young University (International Foundation for Telemetering, 1998-10)
      To help students learn the principles of microwave engineering and electromagnetic theory, labs were developed in which the students built a rail-synthetic aperture radar(SAR) and a Doppler radar. These labs gave the students practical experience in the paper design, simulation, construction, testing, and debugging of RF circuits. This paper includes a description of the design, physical construction, the basic operation, and the results from these projects.
    • A STATUS REPORT OF THE JOINT ADVANCED MISSILE INSTRUMENTATION (JAMI) PROGRAM- AN OSD CENTRAL TEST AND EVALUATION INVESTMENT PROGRAM (CTEIP) INITIATIVE

      Scofield, Don; Powell, Dave; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 1998-10)
      The Joint Advanced Missile Instrumentation (JAMI) Program, a multi-year CTEIP effort, will develop an integrated instrumentation package for tri-Service small missile test and training applications. JAMI will provide telemetry, time-space-position information (TSPI), flight termination and end-game vector scoring in a low-cost, modular package that will allow world-wide test and training, thereby eliminating, in most cases, the need for range-specific (or multi-system) facilities. JAMI will incorporate GPS-based technology as the TSPI and vector scoring engine, as well as state-of-the-art telemetry. JAMI will also address the feasibility of a solid state programmable safe-and-arm device. The effort will include a Test Technology Development and Demonstration (TTD&D) risk reduction phase which will validate tri-service requirements, provide a technology demonstration, and assess the applicability of advanced antenna technology. This paper discusses the progress of the program during the TTD&D phase including preliminary testing of GPS receivers and conformal GPS antennas.