• MANAGEMENT OF NETWORK-BASED FLIGHT TEST SYSTEMS

      Moore, Michael S.; Grim, Evan T.; Kamat, Ganesh U.; Moodie, Myron L.; Southwest Research Institute (International Foundation for Telemetering, 2007-10)
      Network-based instrumentation systems are rapidly replacing traditional fixed serial interconnected instrumentation in both commercial and military flight test environments. Modern network-based flight test systems are composed of large numbers of devices including high-speed network switches, data acquisition devices, recorders, telemetry interfaces, and wireless network transceivers, all of which must be managed in a coordinated fashion. Management of the network system includes configuring, controlling, and monitoring the health and status of the various devices. Configuration by hand is not a realistic option, so algorithms for automatic management must be implemented to make these systems economical and practical. This paper describes the issues that must be addressed for managing network-based flight test systems and describes a network management approach that was developed and employed to manage a large-scale network-based flight test system.
    • MEASUREMENT OF IN-FLIGHT MOTION CHARACTERISTICS OF A HIGH-G LAUNCHED FLARESTABILIZED PROJECTILE WITH ON-BOARD TELEMETRY

      Brown, T. Gordon; Bukowski, Ed; Ilg, Mark; Brandon, Fred; U.S. Army Research Laboratory; Dynamic Science. Inc (International Foundation for Telemetering, 2007-10)
      In pursuit to understanding the flight behavior and characterizing the stability of a flarestabilized projectile, an experiment was conducted to assess the robustness of an inertial sensor suite the size of a dime (17.5mm) by integrating to a telemetry system for recording. The system had to survive launch acceleration exceeding 25,000G’s. This is the beginning of an effort to reduce the size of telemetry systems and diagnostic devices for use in medium caliber munitions and smaller. A description of the telemetry system and subsystem will be presented along with the results.
    • MEASUREMENT-CENTRIC DATA MODEL FOR INSTRUMENTATION CONFIGURATION

      Malatesta, William; Fink, Clay; Naval Air Systems Command; Johns Hopkins University (International Foundation for Telemetering, 2007-10)
      CTEIP has launched the integrated Network Enhanced Telemetry (iNET) project to foster advances in networking and telemetry technology to meet emerging needs of major test programs. In the past these programs have been constrained by vendor proprietary equipment configuration utilities that force a significant learning curve on the part of instrumentation personnel to understand hardware idiosyncrasies and require significant human interaction and manipulation of data to be exchanged between different components of the end-to-end test system. This paper describes an ongoing effort to develop a measurement-centric data model of airborne data acquisition systems. The motivation for developing such a model is to facilitate hardware and software interoperability and to alleviate the need for vendor-specific knowledge on the part of the instrumentation engineer. This goal is driven by requirements derived from scenarios collected by the iNET program. This approach also holds the promise of decreased human interaction with and manipulation of data to be exchanged between system components.
    • META-DATA VERSIONING

      Adamski, Greg; L-3 Communications (International Foundation for Telemetering, 2007-10)
      Telemetry missions spanning multiple years of tests often require access to archived configuration data for replay and analysis purposes. The needs for versioning vary from simple file-naming conventions to advanced global database versioning based on the scale and complexity of the mission. This paper focuses on a flexible approach to allow access to current and past versions of multiple test article configurations. Specifically, this paper discusses the characteristics of a versioning system for user-friendly and feature-rich solutions. It analyzes the tradeoffs of various versioning options to meet the needs of a given mission and provides a simple framework for users to identify their versioning requirements and implementation.
    • METADATA MODELING FOR AIRBORNE DATA ACQUISITION SYSTEMS

      Kupferschmidt, Benjamin; Pesciotta, Eric; Teletronics Technology Corporation (International Foundation for Telemetering, 2007-10)
      Many engineers express frustration with the multitude of vendor specific tools required to describe measurements and configure data acquisition systems. In general, tools are incompatible between vendors, forcing the engineer to enter the same or similar data multiple times. With the emergence of XML technologies, user centric data modeling for the flight test community is now possible. With this new class of technology, a vendor neutral, standard language to define measurements and configure systems may finally be realized. However, the allure of such a universal language can easily become too abstract, making it untenable for hardware configuration and resulting in a low vendor adoption rate. Conversely, a language that caters too much to vendor specific configuration will defeat its purpose. Achieving this careful balance is not trivial, but is possible. Doing so will produce a useful standard without putting it out of the reach of equipment vendors. This paper discusses the concept, merits, and possible solutions for a standard measurement metadata model. Practical solutions using XML and related technologies are discussed.
    • THE MICRO-INSTRUMENTATION PACKAGE: A SOLUTION TO LIGHTWEIGHT BALLOONING

      Juneau, Jill; NASA/Columbia Scientific Balloon Facility (International Foundation for Telemetering, 2007-10)
    • MOBILE GROUND TRACKING STATION DESIGN MODIFICATIONS AND PLACEMENT PREPARATION FOR CROWDED AIRSPACE

      Altan, Hal; Honeywell International (International Foundation for Telemetering, 2007-10)
      As the frequency spectrum becomes more crowded each day, preparation for placement of tracking ground station in tracking environment gains more importance. Existence of high power weather ground radars, airport approach equipment, and various other RF sources in the environment necessitates the test teams to be more cautious. This paper discusses, implemented design changes to an S-band antenna system to reduce the in-band interfering power, calculation of the effects from nearby interferers, analysis of the environment during placement of the mobile ground system by Honeywell telemetry teams.
    • Modeling Channel Estimation Error in Continuously Varying MIMO Channels

      Kosbar, Kurt; Potter, Chris; University of Missouri (International Foundation for Telemetering, 2007-10)
      The accuracy of channel estimation plays a crucial role in the demodulation of data symbols sent across an unknown wireless medium. In this work a new analytical expression for the channel estimation error of a multiple input multiple output (MIMO) system is obtained when the wireless medium is continuously changing in the temporal domain. Numerical examples are provided to illustrate our findings.
    • MODELING OF THE PLASMA FORMATION DUE TO LASER IRRADIENCE DURING DIRECTED-ENERGY TESTING

      Rajendran, Saravanakanthan; Keidar, Michael; Boyd, Iain D.; Jones, Charles H.; Mork, Brian; University of Michigan; Edwards Air Force Base (International Foundation for Telemetering, 2007-10)
      Real-time transmission of airborne images to a ground station is highly desirable in many telemetering applications. Such transmission is often through an error prone, time varying wireless channel, possibly under jamming conditions. Hence, a fast, efficient, scalable, and error resilient image compression scheme is vital to realize the full potential of airborne reconnaisance. JPEG2000, the current international standard for image compression, offers most of these features. However, the computational complexity of JPEG2000 limits its use in some applications. Thus, we present a scalable low complexity coder (SLCC) that possesses many desirable features of JPEG2000, yet having high throughput. Continuous radio-wave telemetry is required during planned tests of directed-energy weapons systems in order to characterize in situ the effects of laser irradiation on different target materials. Unfortunately, the incident radiation can cause disruption of the radio signal during the directed-energy testing. Several phenomena associated with directed-energy impact can lead to communication path losses, such as ablation, charged particle emission, charring, and chemical changes in the target materials. Directed-energy impact on the target material leads to target heating and consequent ablation. In this paper, a numerical model has been developed to describe the laser induced ablation of metal surfaces. The model describes the absorption of the laser energy by the metal and the resulting temperature rise in the surface. This temperature rise then induces ablation of the target material. Results for an aluminum target irradiated with a KrF laser were obtained. Temperature profiles in the target material and surface temperature changes are presented along with the ablation rate as a function of time as the aluminum target is irradiated. This report presents results for cases when laser energy absorption by the plasma plume created above the surface is not significant.
    • A MORE EFFICIENT TRACKING SYSTEM FOR THE SANTIAGO SATELLITE TRACKING STATION

      Ramírez, Eduardo Díaz; Universidad de Chile (International Foundation for Telemetering, 2007-10)
      A digital antenna control system has been designed and installed on a pedestal that was formerly used to drive a VHF array and that has now been replaced with an 11 meter S-Band parabolic reflector. In this Paper, the former analog tracking system will be described, showing all the drawbacks that made it unusable for S-Band. Subsequently, the development and implementation of the digital S-Band tracking system, using Labview, C++ & digital control theory will be discussed. Finally, there will be a comparison between the digital and analog system, too.
    • Multiple Bit Differential Detection of SOQPSK with Diversity Reception

      Perrins, Erik; Ramakrishnan, Madhusudhan; University of Kansas (International Foundation for Telemetering, 2007-10)
      In this paper, we consider multiple bit differential detection (MBDD) of differentially encoded shapedoffset quadrature phase-shift keying (SOQPSK) over slow fading channels, especially Rayleigh fading channels. SOQPSK is a highly bandwidth efficient and popular form of constant envelope continuous phase modulation (CPM). We present two versions of the MBDD algorithm: the full-size version (FMBDD) which uses a detection window that spans the entire N-bit observation window, and an improved version (I-MBDD) which maintains the original N-bit observation window but detects only N − 2 bits within the window. The complexity of both algorithms is shown to increase linearly with the order of diversity reception, L, and exponentially with the size of the observation window, N; the I-MBDD achieves the best performance for given values of L and N. As expected, the performance in the case of diversity reception shows a marked improvement over the single channel case.
    • MULTIPLE TIME BASE SYCHRONIZATION PROCESS APPLIED TO THE FLIGHT TESTS CAMPAIGN OF A GPS ATTITUDE DETERMINATION ALGORITM

      Leite, Nelson Paiva Oliveira; Walter, Fernando; CTA - Grupo Especial de Ensaios em Vôo; ITA - Divisão de Eletrônica (International Foundation for Telemetering, 2007-10)
      For the final evaluation of a GPS attitude determination algorithm, it was determined its true performance in terms of its accuracy, reliability and dynamic response. To accomplish that, a flight test campaign was carried out to validate the attitude determination algorithm. In this phase, the measured aircraft attitude was compared to a reference attitude, to allow the determination of the errors. The system was built using non-dedicated THALES Z-FX airborne GPS receivers and a complete Flight Tests Instrumentation (FTI) System. Each GPS receiver operates synchronized with its internal time base. The FTI measurements are synchronized to an IRIG-B time base. All time bases have their own random walk characteristic. To avoid C/A code ambiguity, when its internal time base approaches ±1ms error from the GPS time, its clock is then corrected causing time and phase observables discontinuities. A multiple time base synchronization process was developed to correlate GPS and FTI data. The results are presented and the residual errors were considered acceptable. These data allowed the determination of the performance and accuracy of the GPS attitude determination algorithm. The tests profiles are fully compliant with the Federal Aviation Administration (FAA) Advisory Circular (AC) 25-7A.
    • NET-CENTRIFYING THE GOULD TA6000 OSCILLOGRAPH

      Guadiana, Juan; Benitez, Jesus; Tiqui, Dwight; White Sands Missile Range (International Foundation for Telemetering, 2007-10)
      Migrating analog architectures and equipments to network architectures is underway all across the globe. There is no doubt, a modern instrument must fit the network environment or simply will not be procured. Yet, funding constraints temper wholesale changes to net-centric technologies. The last analog stronghold in our data center is the oscillograph. Over 50 Gould TA 6000 Oscillographs reside at White Sands Missile Range. These are digital implementations of analog recorders, hence require analog signaling. Digital telemetry data (most common format) must be converted to analog to drive an oscillograph that converts analog back to digital to plot the data. The oscillograph’s interface board may be “hacked” by removing the Analog to Digital Converter (ADC) gaining direct access to the digital signal path. This idea was worth attempting as the prospect of replacing that many recorders with the newer network driven oscillographs is costly hence remote. This paper’s topic is the conversion of the hardware and a discussion on software issues. Though not pretty, it does preserve the large recorder investment for the time being. Issues with analog signaling, such as noise, drift and ground loops are gone. A commercial ethernet to digital adapter drives the new digital interface and transforms the recorder into an net-centric instrument.
    • NETGEN: A MODEL-DRIVEN TOOL FOR RAPID PROTOTYPING AND SIMULATION OF NETWORK-BASED FLIGHT TEST SYSTEMS

      Price, Jeremy C.; Moore, Michael S.; Southwest Research Institute (International Foundation for Telemetering, 2007-10)
      When network-centric flight test system components are developed concurrently, it is necessary to produce relevant simulated network traffic for exercising the network devices and other processing subsystems prior to system integration. Having an accurate and repeatable pattern of simulated network traffic is extremely important for debugging and subsystem integration. The simulated network traffic must be both representative of the real system and repeatable to aid test efforts. Our solution to this problem was to develop a model-driven network traffic generator – NETGEN. Using NETGEN to resolve errors, stress test, and verify requirements, we have achieved otherwise unattainable correctness, reliability, and success in our systems.
    • Network Design Considerations in Telemetry Systems

      Grebe, Andy; Klein, Wayne; Apogee Labs, Inc. (International Foundation for Telemetering, 2007-10)
      In today’s world, computer networking has become common place both in industry as well as home, however all networks are not the same! The Telemetry world, like with many industries, has critical design considerations that need to be evaluated when you begin a new system or just adding on to a current infrastructure. This paper is intended to outline needed considerations when planning or implementing a network design in Telemetry Systems. These applications can range from sensor data transport through High Definition/High Speed Video applications.
    • NETWORK-BASED DISTRIBUTED DATA ACQUISITION AND RECORDING FOR SMALL SYSTEMS

      Hildin, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2007-10)
      Some of the first applications of network-based data acquisition systems have been for large aircraft. These systems contained numerous network nodes including data acquisition units, switches, recorders, network management units, and others. One of the desirable aspects of a networked-based system is the ability to scale such a system to meet increasing test requirements. Similarly, these systems lend themselves to scaling down, as well, to meet the testing needs of smaller test articles. These needs may include fewer nodes and/or physically smaller components. The testing of smaller vehicles places slightly different requirements on the testing process. In general, there is a greater need for real-time analysis, flexibility and ad-hoc testing. This paper will attempt to show how a small to medium sized test article can benefit from the same powerful, feature-rich network-based data acquisition and recording system as used on larger programs. The paper will also show how a smaller system can deliver on this promise without sacrificing performance and functionality.
    • A NEXT GENERATION AIRCRAFT POWER MONITORING SYSTEM

      Grossman, Hy; Teletronics Technology Corporation (International Foundation for Telemetering, 2007-10)
      Historically, aircraft power monitoring has required the use of multiple signal conditioning functions to measure various parameters including voltage, current, frequency and phase. This information was then post processed to determine the characteristics of the 3-phase power quality on the aircraft. Recent developments in embedded DSP processors within signalconditioning systems provide the instrumentation engineer with expanded capabilities for realtime on-board power quality monitoring. Advantages include reduced space and bandwidth requirements and minimal wiring intrusion. For each phase, output data may include peak positive and negative voltages and currents, peak-to-peak, average and RMS voltages and currents, phase power (real and apparent), phase power factor, phase period (frequency), phase shift measurement from phase 1 (the reference phase) to phase 2, and from phase 1 to phase 3. In addition, a Fast Fourier Transform (FFT) is performed on each phase voltage to provide Total Harmonic Distortion measurements. This paper describes the methods employed in the implementation of these functions on a single signal-conditioning card in order to provide detailed information about the power quality of a three-phase aircraft power source.
    • ON REDUCED COMPLEXITY TECHNIQUES FOR BANDWIDTH EFFICIENT CONTINUOUS PHASE MODULATIONS IN SERIALLY CONCATENATED CODED SYSTEMS

      Perrins, Erik; Kumaraswamy, Dileep; University of Kansas (International Foundation for Telemetering, 2007-10)
      Serially concatenated coded (SCC) systems with continuous phase modulations (CPMs) as recursive inner codes have been known to give very high coding gains at low operative signal to noise ratios (SNRs). Moreover, concatenated coded systems with iterative decoding approach the bit error rate (BER) bounds given by the maximum likelihood (ML) criterion. Although SCC systems by themselves are reduced complexity systems when compared to the ML decoding, when very highly bandwidth efficient CPMs such as pulse code modulation /frequency modulation (PCM/FM) is used [1], they present a problem of extremely high decoding complexity at the receiver. The complexity of a CPM is described by the size of its trellis which is a function of the modulation index, the cardinality of the source alphabet and the length of the frequency pulse used. The surveyed complexity reduction techniques adopt approximations which will reduce the size of the trellis with minimal expense of power. In this paper, we present reduced complexity approaches to sub-optimally decode SCC PCM/FM by mainly two approaches - 1) Frequency pulse truncation. 2) Decision feedback.
    • OPERATOR INTERFACES FOR CONTROLLING THE SERIAL STREAMING TELEMETRY CHANNEL VIA A COMMAND AND CONTROL LINK

      Laird, Daniel T.; Edwards Air Force Base (International Foundation for Telemetering, 2007-10)
      The Central Test and Evaluation Incentive Program, (CTEIP) is developing Integrated Network Enhanced Telemetry (iNET) to extend serial streaming telemetry (SST) with a command and control link. Command link interfaces link remote Advanced Range Telemetry (ARTM) transmitters (Tx) and receivers (Rx), developed under the ARTM CTEIP project, via graphical user interfaces (GUI). The communication channel links the iNET Tx on a vehicle network (vNET) and the iNET Rx on a ground station network (gNET) via a single GUI. The command link is an essential part of the pending iNET Technology Demonstration.
    • OPTIMAL CONFIGURATION FOR NODES IN MIXED CELLULAR AND MOBILE AD HOC NETWORK FOR INET

      Dean, Richard; Babalola, Olusola; Morgan State University (International Foundation for Telemetering, 2007-10)
      As part of Morgan’s iNET development, the Mixed Cellular and Mobile Ad hoc Network (MCMN) architecture has been 1proposed to provide coverage to over-the horizon test articles. Nodes in MCMN are assigned to one of three possible modes- Ad hoc, Cellular or Gateway. We present architecture for the proposed MCMN and some performance analysis to characterize the network. The problem of organizing nodes in this mixed network with optimal configuration is significant. This configuration gives nodes ability to know the best mode to operate and communicate with other nodes. Node organization is critical to the performance of the mixed network and to improve communication. The configuration of nodes required to optimally organize nodes in MCMN is demonstrated. The problem of evaluating configuration parameters for nodes in a mixed network is a nonlinear and complex one. This is due to the various components like the number of nodes, geographical location, signal strength, mobility, connectivity and others that are involved. Clustering techniques and algorithms have been used in literature to partition networks into clusters to support routing and network management. A clustering technique is employed to dynamically partition the aggregate network into Cluster Cells (CCs). A gateway node is selected for each CC which relays traffic from the cellular to the Ad hoc and vice versa. A trade-off analysis of the cellular boundary is presented using the maximum of the minimum data rate in the network. Numerical analysis and experiments are provided to show that the coverage can be extended to test articles in over-the-horizon region. It is also shown that, when the network is well organized, performance is improved.