• The Software Decommutation Model (SDM)

      Creel, Larry; Engler, Richard; Alexis Telemetry, Incorporated; White Sands Missile Range (International Foundation for Telemetering, 2009-10)
      It is well known that current PCM telemetry formats are outstripping the capability of commercial off-the-shelf (COTS) Telemetry Systems to implement the corresponding data conversions required to process them. Two complementary approaches are needed for solving this problem: one is to put end users into direct touch with the information stored in telemetry streams; and the other is to convert telemetry applications into this new way of doing things. It is less known that a single technology, software decommutation, provides a practical foundation for both approaches. This document explains why this is so. While developing this software decommutation theme, a very sharp line must be drawn between a software decommutation approach and the COTS telemetry systems solution so that the label "software decommutation" will not be used in misleading ways. The key to drawing this line is SDM's (Software Decommutation Model) ability to: * Extract bits from the raw telemetry stream into 64-bit parameter "containers" in a platform independent ("big endian" or "little endian") manner. * Process algorithms in an algorithm chain on telemetry parameter data to support the desired formatting (i.e. engineering unit conversion). * Easily integrate "special" processing of non-IRIG 106 telemetry data as required (i.e. multiple embedded streams, mode changes, embedded packetized data, etc.). * Independently interface to user-developed data displays locally or via a network connection. *Note: The SDM cannot process a PCM stream directly; to do its job, a databridge is required that provides telemetry data as frame aligned IP packets via a network port.
    • Pacific Ranges Interoperable Test & Evaluation Capabilities (PRITEC)

      Hermann, Scott A.; Wigent, Mark A.; Chavez, Tomas C.; PMRF; SAIC; CSC (International Foundation for Telemetering, 2009-10)
      The office of the Defense Test Resources Management Center (DTRMC) has developed two major programs to achieve Joint/Interoperable exercises between DoD test and training ranges. Joint Mission Environment Test Capability (JMETC) defines a LVC environment in which Joint operations take place, while the Test and Training Enabling Architecture (TENA) defines the communication within that environment. Putting these programs to everyday use has been a challenge for the ranges. The Pacific Missile Range Facility (PMRF) is executing the Central Test & Evaluation Investment Program (CTEIP) sponsored Pacific Ranges Interoperable Test & Evaluation Capabilities (PRITEC) project designed to develop a set of tools that will facilitate implementation of JMETC and TENA. This paper will discuss the PRITEC project in detail.
    • Data Flow and Remote Control in the Telemetry Network System

      Laird, Daniel T.; Morgan, Jon; Edwards Air Force Base (International Foundation for Telemetering, 2009-10)
      The Central Test and Evaluation Investment Program (CTEIP) Integrated Network Enhanced Telemetry (iNET) program is currently developing new standards for wired-wireless local area networking (LAN-WLAN) using the Internet Protocol (IP), for use in telemetry (TM) channels, under the umbrella of the Telemetry Network System (TmNS). Some advantages of TmNS are real-time command and control of instrumentation, quick-look acquisition, data retransmission and recovery ('gapless TM' or 'PCM backfill'), data segmentation, etc. The iNET team is developing and evaluating prototypes, based on commercial 802.x and other technologies, in conjunction with Range Commander's Council (RCC) Inter-Range Instrumentation Group (IRIG) standards and standards developed under the iNET program.
    • Using Telemetry Science, An Adaptation of Prognostic Algorithms for Predicting Normal Space Vehicle Telemetry Behavior from Space for Earth and Lunar Satellites and Interplanetary Spacecraft

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2009-10)
      Prognostic technology uses a series of algorithms, combined forms a prognostic-based inference engine (PBIE) for the identification of deterministic behavior embedded in completely normal appearing telemetry from fully functional equipment. The algorithms used to define normal behavior in the PBIE from which deterministic behavior is identified can be adapted to quantify normal spacecraft telemetry behavior while in orbit about a moon or planet or during interplanetary travel. Time-series analog engineering data (telemetry) from orbiting satellites and interplanetary spacecraft are defined by harmonic and non-harmonic influences which shape it behavior. Spectrum analysis can be used to understand and quantify the fundamental behavior of spacecraft analog telemetry and relate the behavior's frequency and phase to its time-series behavior through Fourier analysis.
    • Strategies for Optimized Spectrum Allocation and Management

      Painter, Mike K.; Fernandes, Ronald; Ramachandran, Satheesh; Verma, Ajay; Jones, Charles H.; Knowledge Based Systems, Inc.; Edwards Air Force Base (International Foundation for Telemetering, 2009-10)
      This paper describes research aimed at investigating how to help decision makers devise optimized frequency scheduling and management strategies, both for advanced planning and real-time metrics adjustment. Part of these investigations include research to (i) define the metrics, objectives, and constraints involved in optimal frequency allocation decision-making; (ii) harmonize competing, orthogonal goals when devising candidate solutions; and (iii) devise an architectural strategy for dynamic spectrum allocation and management.
    • Design Considerations for Networked Data Acquisition Systems

      Cranley, Nikki; Corry, Diarmuid; ACRA Control Inc. (International Foundation for Telemetering, 2009-10)
      Ethernet technology offers numerous benefits for networked Flight Test Instrumentation (FTI) systems such as increased data rates, flexibility, scalability and most importantly interoperability owing to the inherent interface, protocol and technological standardization. However, the best effort nature of Ethernet is in sharp contrast to the intrinsic determinism of tradition FTI systems. The challenge for network designers is to optimize the configuration of the Ethernet network to meet the data processing demands in terms of reliability and latency. This paper discusses the necessary planning and design phases to investigate, analyze, fine-tune and optimize the networks performance.
    • Improved Error Performance in SOQPSK Modulation Using a Ternary Symbol Encoder

      Counsil, David T.; Punnoose, Ratish J.; Sandia National Laboratories (International Foundation for Telemetering, 2009-10)
      Telemetry transmissions have been evolving over the recent years from PCM/FM to other constant envelope modulation schemes such as SOQPSK and multi-h CPM. These newer modulations schemes have better spectral efficiency but tend to have worse error performance than optimally detected PCM/FM. We present a new ternary symbol encoder to replace the existing differential encoder and pre-coder for SOQPSK. This improves error performance while minimally affecting the spectral properties. The "reach" of the new ternary code length is not much longer than current symbol encoder, so there will not be a significant increase in synchronization time in the receiver. We provide simulation results showing the increased performance. Along the way, we also provide a simplified view of the current SOQPSK differential encoder and pre-coder.
    • Performance of an OFDM-Based DVB-T System and its FPGA Implementation

      Yang, Luyu; Song, Peng; Song, Qingping; North China University of Technology (International Foundation for Telemetering, 2009-10)
      Orthogonal frequency division multiplexing (OFDM) is a new technique for data transmission. Conforming to the final draft of OFDM-based DVB-T (ETSI EN 300 744 V1.6.1), which is intended for digital terrestrial television broadcasting, a DVB-T baseband system is designed. The system performance is simulated in MATLAB using Simulink. Then it is implemented on Field Programmable Gate Array (FPGA) with the help of System Generator software. The result shows that OFDM is robust against multipath effect and convenient for implementation as well, thus owning a quite promising future.
    • A System-Level Description of a SOQPSK-TG Demodulator for FEC Applications

      Perrins, Erik; Rea, Gino; University of Kansas (International Foundation for Telemetering, 2009-10)
      In this paper we present a system-level description of a demodulator for shaped offset quadrature phase shift keying, telemetry group version (SOQPSK-TG) for use in forward error correction (FEC) applications. We describe the system in block-diagram form and provide implementation details for data sequence detection, symbol timing synchronization, carrier phase synchronization, and block recovery. This decision-directed demodulator is based on maximum likelihood principles, and is efficiently implemented by the soft output Viterbi algorithm (SOVA). We also provide results of the demodulator's performance in the additive white Gaussian noise channel, based on the observed bit error rate at different signal-to-noise ratio levels.
    • OFDM Performance on Aeronautical Channnels

      Dean, Richard; Kamirah, Daniel K.; Morgan State University (International Foundation for Telemetering, 2009-10)
      This paper provides an introduction to the Orthogonal Frequency Division Multiplexing (OFDM) scheme which has been proposed for future aeronautical telemetry applications. OFDM offers the potential for high data rates on radio channels with multipath such as aeronautical telemetry channels. This paper provides in introduction to OFDM and demonstrates how orthogonality is maintained over multipath channels by the introduction of a guard band and by the inclusion of a cyclic prefix. The simulation of OFDM in multipath is simulated and performance results are presented that show the degradation of this scheme on a multipath channel with and without the guard band and the cyclic prefix.
    • Low Noise Amplifiers with High Dynamic Range

      Ridgeway, Robert; Digi International (International Foundation for Telemetering, 2009-10)
      This new transistor will make it possible to achieve signal to noise ratio improvements of up to 15 dB (six times more link distance) for systems where the antenna looks sky ward. Using this type of low noise pHEMT device for on the horizon links insures that the telemetry link will be limited only by the natural thermal radio back ground noise and not by the receivers noise.
    • Antenna Tracking and Command Destruct Capabilities Based on Angular Velocity and Acceleration

      Altan, Hal; Honeywell International (International Foundation for Telemetering, 2009-10)
      Most range safety telemetry tracking systems have antenna designs that feature an S-band (2200-2400 MHz) Telemetry Tracking and UHF-Band (400-450 MHz) Command Destruct feed along side an omni-directional antenna. The antennas must have, by design, high angular velocity (w) and acceleration (α) parameters to achieve these tasks. Generally, these parameters are user configurable through software and monitored through BIT (Built In Test) log files. The parameters are nominally set to their maximum values (ie. w=10 deg/sec and α = 15 deg/sec².) Considering the dynamics of a sample satellite launch vs. the ground tracking and omni antennas' combined capabilities, this document analyzes whether the target will stay within the beam.
    • Direct Spatial Antenna Modulation for Phased-Array Applications

      Uhl, Brecken; Invertix Corporation (International Foundation for Telemetering, 2009-10)
      New technologies are sought to meet the requirements of evolving telemetry capabilities such as new operating bands, increased test article and ground segment collaboration, and on-the-fly quality of service (QOS) management. Smart antennas may contribute to this evolution by directing signal energy where and when it is needed. Direct spatial antenna modulation (DSAM) represents a new approach to cost-effective smart antennas potentially offering benefits such as post-amplifier modulation, polarization reconfigurability, phase-shifterless phased arrays, oscillator-less frequency conversion, and pre-receiver processing gain. The basic DSAM approach has recently been proven through analysis, simulation, and prototyping, with significant implications for future capabilities.
    • Development of a Synthetic Beamforming Antenna - From Drawing Board to Reality

      Kelkar, Anand; Lamarra, Norm; Vaughan, Thomas; Creative Digital Systems (International Foundation for Telemetering, 2009-10)
      Following-up on an ITC 2006 paper, "From RF to bits with Synthetic Beamforming", we follow the development and fielding of a Digital Beamforming (DBF) Antenna. This antenna, built for an airborne Telemetry application, supports 10 individual polarization-diverse beams and immediately converts RF to IF at the antenna element through a suite of LNBs. The IF is then digitized and all subsequent processing is performed through an array of 200+ FPGAs, including DBF, optimal combining, demodulation, and IF upconversion. We present our Model-Based Design approach, which allowed us to develop and test the system incrementally and rapidly, particularly during the transition from factory testing to flight operations, where several unexpected problems were discovered. Our software tool set enabled us to dissect the System behavior via post-mission replay, and our detailed simulations were instrumental in developing mitigation quickly. The System-level impacts and root causes of some of these issues are also discussed. We believe the flexibility of DBF and the modular software architecture were key in quickly mitigating many of these unforeseen real-world issues without hardware modification.
    • Multipath Mitigation for Aeronautical Telemetry with Multiple Antennas

      Saquib, M.; Williams, Ian E.; University of Texas at Dallas (International Foundation for Telemetering, 2009-10)
      Frequency selective multipath is a key performance limiter for aeronautical telemetry applications. Our research explores multipath mitigation techniques with ARTM Tier-1 waveforms using linear adaptive filters, multiple receive antennas and error-based best source selection. Single antenna adaptive equalization alone is unable to substantially improve performance under certain channel conditions. Analytical investigations demonstrate that nonlinear channel phase response is the principal cause of performance loss. In this adverse environment, spatial diversity with multiple receive antennas along with error-based best source selection are capable of improving bit error rate performance by 5dB for each additional antenna.
    • Electrostatic Approach for Mitigation of Communication Attenuation During Directed Energy Testing

      Kundrapu, Madhusudhan; Keidar, Michael; Jones, Charles; George Washington University; Edwards Air Force Base (International Foundation for Telemetering, 2009-10)
      Electrostatic approach is considered for mitigation of communication attenuation during the testing of laser powered directed energy weapon. Mitigation analysis is carried out for two target materials Al and Ti. Plasma parameters are obtained using one dimensional coupled analysis of laser-target interaction. Influence of laser beam frequency on plasma parameters is addressed. Sheath thickness is obtained using transient sheath calculations. It is found that uninterrupted telemetry can be achieved | using a maximum bias voltage of 10 kV, through Al plasma for fluences below 5 J/cm² and through Ti plasma for fluences below 2 J/cm².
    • Using Oracol® for Predicting Long-Term Telemetry Behavior for Earth and Lunar Orbiting and Interplanetary Spacecraft

      Losik, Len; Failure Analysis (International Foundation for Telemetering, 2009-10)
      Providing normal telemetry behavior predictions prior to and post launch will help to stop surprise catastrophic satellite and spacecraft equipment failures. In-orbit spacecraft fail from surprise equipment failures that can result from not having normal telemetry behavior available for comparison with actual behavior catching satellite engineers by surprise. Some surprise equipment failures lead to the total loss of the satellite or spacecraft. Some recovery actions as a consequence of a surprise equipment failure are high risk and involve decisions requiring a level of experience far beyond the responsible engineers.
    • Data Acquisition Blasts Off - Space Flight Testing

      Curry, Diarmuid; ACRA Control Inc. (International Foundation for Telemetering, 2009-10)
      In principle, the requirements for a flight test data acquisition system for space testing (launch vehicles, orbiters, satellites and International Space Station (ISS) installations) are very similar to those for more earth-bound applications. In practice, there are important environmental and operational differences that present challenges for both users and vendors of flight test equipment. Environmental issues include the severe vibration and shock experienced on take-off, followed by a very sharp thermal shock, culminating (for orbital vehicles) in a low temperature, low pressure, high radiation operating environment. Operational issues can include the need to dynamically adapt to changing configurations (for example when an instrumented stage is released) and the difficulty in Telemetering data during the initial launch stage from a vehicle that may not be recoverable, and therefore does not offer the option of an on-board recorder. Addressing these challenges requires simple, rugged and flexible solutions. Traditionally these solutions have been bespoke, specifically designed equipment. In an increasingly cost-conscious environment engineers are now looking to commercial off-the-shelf solutions. This paper discusses these solutions and highlights the issues that instrumentation engineers need to consider when designing or selecting flight test equipment.
    • Potential Solutions to Communications During Plasmasonic Flight

      Jones, Charles H.; Air Force Flight Test Center (International Foundation for Telemetering, 2009-10)
      At about Mach number 10 and above, a high energy plasma field forms around a vehicle. This plasma sheath has a high attenuation factor that can cause communications black out. No practical solutions to communicating through a plasma sheath are known. In addition to standard real time data needs for test, a driving requirement to solve this problem is that most solutions will have to be designed into the vehicle. Modifications of vehicles designed to travel at these Mach numbers, especially any exterior modifications, will be extremely difficult due to effects on aerodynamics, thermal protection, and the materials used. A list of possible solutions to communications through hypersonically induced plasma has been collected over several years. This list was added to and verified during the Workshop on Communications through Plasma during Hypersonic Flight. Pros and cons of these potential solutions have been discussed and documented as well. The workshop also included a vote by the attending experts on what solutions are most promising. This paper reviews these solutions, their pros and cons, and a recommended way forward to solving this problem.
    • Performance Analysis of Reentry TDOA Positioning System

      Nan, Xie; Futang, Zhang; China Academy of Engineering Physics (International Foundation for Telemetering, 2009-10)
      In reentry measurement, we need to measure the track of reentry vehicle. For the speed of target is very high, it is difficult for traditional positioning system to capture and track the target. TDOA (time difference of arrival) positioning system is used in reentry measurement. The position of target is calculated by using time difference of arrival. This paper introduces the principle of reentry TDOA positioning system. The key technology is synchronization of ground stations' clocks. The implementation of clock synchronization using low-cost commercial GPS receiver is presented. The sources of errors in the existing telemetry system, corresponding precision and experimental results are presented. Some methods, which are used to improve the precision, are proposed at the end of this paper.