• International Telemetering Conference Proceedings, Volume 43 (2007)

      International Foundation for Telemetering, 2007-10
    • DESIGN OF A CONFIGURATIONAND MANAGEMENT TOOL FORINSTRUMENTATION NETWORKS

      Roach, John; Teletronics Technology Corporation (International Foundation for Telemetering, 2007-10)
      The development of network-based data acquisition systems has resulted in a new architecture for supporting flight instrumentation that has the potential to revolutionize the way we test our aircraft. However, the inherent capability and flexibility in a networked test architecture can only be realized by the flight engineer if a sufficiently powerful toolset is available that can configure and manage the system. This paper introduces the concept of an instrumentation configuration and management system (ICMS) that acts as the central resource for configuring, controlling, and monitoring the instrumentation network. Typically, the ICMS supports a graphical user interface into the workings of the instrumentation network, providing the user with a friendly and efficient way to verify the operation of the system. Statistics being gathered at different peripherals within the network would be collected by this tool and formatted for interpretation by the user. Any error conditions or out-of-bounds situations would be detected by the ICMS and signaled to the user. Changes made to the operation of any of the peripherals in the network (if permitted) would be managed by the ICMS to ensure consistency of the system. Furthermore, the ICMS could guarantee that the appropriate procedures were being followed and that the operator had the required privileges needed to make any changes. This paper describes the high-level design of a modular and multi-platform ICMS and its use within the measurement-centric aircraft instrumentation network architecture under development by the Network Products Division at Teletronics.
    • TELEMETRY AND COMMAND FRAME ROUTING IN A MULTI-MISSION ENVIRONMENT

      Bester, Manfred; Stroozas, Brett; Bester Tracking Systems, Inc.; Stroozas Flight Ops (International Foundation for Telemetering, 2007-10)
      In a modern ground control network for space communications, secure peer-to-peer TCP/IP network socket connections are typically used to transfer real-time telemetry and command frames between satellite operations centers and remote ground stations. Reliable and timely reconfiguration of data paths for upcoming pass supports becomes rather complex when many spacecraft and ground stations are involved. This paper describes a routing software application that was developed to facilitate switching of telemetry and command data paths between multiple ground stations and spacecraft command and control systems, and to forward telemetry streams to multiple client applications in parallel. Fully automated configuration and monitoring of the data flows is accomplished via a remote control interface that is tied into a pass scheduling system. The software is part of the SatTrack Suite and currently supports multi-mission flight operations, including those of the recently launched THEMIS constellation mission at Space Sciences Laboratory, University of California at Berkeley.
    • XML META-DATA EXPERIMENTS

      K/Bidy, Gilles; L-3 Communications (International Foundation for Telemetering, 2007-10)
      As part of the technology upgrades driven by the iNet initiative, there is a need to establish a meta-data standard to describe configuration information for the system under test. The technology identified for such a standard is XML and XSD schemas. This paper presents findings from various experiments to import and export existing telemetry configuration information to XML based on the new Meta-data model. In addition, this paper will discuss the possible conversions to and from the existing IRIG TMATS standard.
    • REORDERING PACKET BASED DATA IN REAL-TIME DATA ACQUISITION SYSTEMS

      Kilpatrick, Stephen; Rasche, Galen; Cunningham, Chris; Moodie, Myron; Abbott, Ben; Southwest Research Institute (International Foundation for Telemetering, 2007-10)
      Ubiquitous internet protocol (IP) hardware has reached performance and capability levels that allow its use in data collection and real-time processing applications. Recent development experience with IP-based airborne data acquisition systems has shown that the open, pre-existing IP tools, standards, and capabilities support this form of distribution and sharing of data quite nicely, especially when combined with IP multicast. Unfortunately, the packet based nature of our approach also posed some problems that required special handling to achieve performance requirements. We have developed methods and algorithms for the filtering, selecting, and retiming problems associated with packet-based systems and present our approach in this paper.
    • L AND S BAND TUNABLE FILTERS PROVIDE DRAMATIC IMPROVEMENTS IN TELEMETRY SYSTEMS

      Wurth, Timothy J.; Rodzinak, Jason; NuWaves Engineering (International Foundation for Telemetering, 2007-10)
      Meeting the filtering requirements for telemetry transmitters and receivers can be challenging. Telemetry systems use filters to eliminate unwanted spurious or mixing products. The use of tunable microwave filters for both L and S Band can improve filter selectivity and provide low insertion losses in the filter passband. Along with meeting specifications, these microwave filters with the ability to tune an octave, reduce size and cost by the reduction of multiple, fixed-frequency filters. As size, weight and power are often a concern with aeronautical telemetry systems, this paper will demonstrate that microstrip tunable filters can be small in size and use minimal power. Telemetry transmitters are subject to difficult spurious emission and interference specifications and require selective filters to eliminate spurious signals before the final amplification. Telemetry receivers on the other hand are subject to intense Image and Local Oscillator (LO) rejection requirements and demand low insertion loss for front-end filtering. Low insertion loss filtering before the Low Noise Amplifier (LNA) circuit limits degradation to the system noise figure (NF). By using different filter topologies and state-of-the-art, high-Q varactor diodes, tunable microwave filters can be optimized for two different functions. The two functions emphasize either low insertion loss or selectivity. An important design consideration with tunable filters, when compared to typical fixed frequency filters, is the degraded intermodulation performance. This is largely due to the non-linear behavior of the varactor diodes. This paper describes the benefits and limitations of microwave tunable filter architectures suitable for both aeronautical telemetry transmitters and telemetry receivers. Information on the computer modeling of varactor diodes will be covered as a critical part of the design. Potential design considerations for microwave tunable filters will also be covered. Through the use of simulation software and filter prototypes, this paper presents dramatically improved filter performance applicable to telemetry transmitters and receivers.
    • ROBUST ADAPTIVE BEAMFORMING WITH BROAD NULLS

      Yudong, He; Xianghua, Yang; Jie, Zhou; Banghua, Zhou; Beibei, Shao; Tsinghua University; China Academy of Engineering Physics (International Foundation for Telemetering, 2007-10)
      Robust adaptive beamforming using worst-case performance optimization is developed in recent years. It had good performance against array response errors, but it cannot reject strong interferences. In this paper, we propose a scheme for robust adaptive beamforming with broad nulls to reject strong interferences. We add a quadratic constraint to suppress the power of the array response over a spatial region of the interferences. The optimal weighting vector is then obtained by minimizing the power of the array output subject to quadratic constrains on the desired signal and interferences, respectively. We derive the formulations for the optimization problem and solve it efficiently using Newton recursive algorithm. Numerical examples are presented to compare the performances of the robust adaptive beamforming with no null constrains, sharp nulls and broad nulls. The results show its powerful ability to reject strong interferences.
    • LOW-NOISE SWITCHING POWER SUPPLY CONSIDERATIONS FOR TELEMETRY ENCODER APPLICATIONS

      Lee, Jeffrey C.; Steppler, Missy; L-3 Communications (International Foundation for Telemetering, 2007-10)
      Modern telemetry systems using state of the art field programmable gate arrays (FPGAs) and signal processing components require lower voltage supplies to support various CMOS core geometries while still needing multiple higher voltage rails to support legacy interfaces. Addressing these power supply requirements efficiently requires switching power supply topologies that if left unchecked can generate high input surge currents and high levels of detrimental noise for both the sensitive analog signal processing circuitry and the power supply input source. This paper focuses on the design considerations and tradeoffs associated with implementing an efficient telemetry encoder power supply while mitigating the resulting noise effects typically associated with switching power supplies. This noise can negatively affect the power supply input source and the linear signal processing circuitry within the telemetry encoder.
    • EVALUATION OF COMMERCIAL-OFF-THE-SHELF LITHIUM BATTERIES FOR USE IN BALLISTIC TELEMETRY SYSTEMS

      Bukowski, Edward F.; U.S. Army Research Laboratory (International Foundation for Telemetering, 2007-10)
      As technological advances continue to be made in the commercial sectors of portable and wireless communication products, additional advancements in battery technology have also been made. These advancements have allowed for the rapid growth of a large variety of commercially available batteries which have the capability to meet or even exceed the current power and size requirements for numerous ballistic telemetry systems. The replacement of a custom built battery with a COTS battery would provide immediate advantages such as lower cost, shorter lead times and higher availability. The overall objective of this paper is to provide ballistic telemetry systems engineers and designers with multiple low cost, readily available alternatives to traditional custom made power sources.
    • DATA DISPLAY INTERCHANGEABILITY FOR HETEROGENEOUS PLATFORMS

      Ross, Robert W.; K/Bidy, Gilles; L-3 Communications (International Foundation for Telemetering, 2007-10)
      A test range facility may consist of a heterogeneous array of computer and workstation assets, given the need to support various new and legacy projects. The data display and analysis software for this heterogeneous environment can be equally diverse, with different application software available and/or supported on the workstations. The demands of managing an operator team skilled in the use of the various software applications, along with the support and maintenance costs, can be restrictive to a cost-effective and productive operation environment. The need for data display and analysis software that can run on all platforms in a heterogeneous environment plays a major role in creating an effective workforce capable of supporting multiple projects without the need to specialize on specific data display software. Likewise, the costs of maintenance and support are greatly reduced. A pure Java™ data display and analysis software product can meet the requirements of this need.
    • UNLEASHING THE POWER OF XML

      Corry, Diarmuid; ACRA CONTROL Inc (International Foundation for Telemetering, 2007-10)
      Over the last few years XML has been growing in importance as a language for describing the meta-data associated with a complete flight test. Three years ago ACRA CONTROL introduced XidML as an open, published XML standard describing flight test data acquisition from the air to the ground. Recently, XML has been adopted by the TMATS RCC committee and is currently being studied by iNET. While many papers have focused on what XML is and why it is a powerful language, few have related this to practical benefits for the end user. This paper attempts to address this gap. The paper describes simple cost effective tools for generating XML through an intuitive GUI, validating XML information against a schema and transforming XML into useful reports. In particular a suite of value added tools for XidML is described.
    • PLASMA DENSITY REDUCTION USING ELECTROMAGNETIC E×B FIELD DURING REENTRY FLIGHT

      Kim, Minkwan; Keidar, Michael; Boyd, Iain D.; Morris, David; University of Michigan; ElectroDynamic Applications Inc. (International Foundation for Telemetering, 2007-10)
      As a vehicle reenters or flies at hypersonic speed through the atmosphere, the surrounding air is shock heated and becomes weakly ionized. The plasma layer thus formed causes a communication problem known as ‘radio blackout’. At sufficiently dense plasma conditions, the plasma layer either reflects or attenuates radio wave communications to and from the vehicle. In this paper, we propose an electromagnetic field configuration as a method to allow communication through the plasma layer. Theoretical models show that this may address the blackout problem under a range of conditions. Preliminary experimental results are also presented.
    • DEVELOPMENT OF A NETWORK-CENTRIC DATA ACQUISITION, RECORDING, AND TELEMETRY SYSTEM

      Moodie, Myron; Newton, Todd; Abbott, Ben; Southwest Research Institute (International Foundation for Telemetering, 2007-10)
      The growth of the Internet and the resulting increasing speeds and decreasing prices of network equipment have spurred much interest in applying networks to flight test applications. However, the best-effort, variable-latency nature of network transport causes challenges that must be addressed to provide reliable data acquisition and timing performance. This paper describes the major issues that must be addressed when designing and implementing real-time networking applications. An overview of a recently implemented large-scale, network-centric data acquisition, recording, and telemetry system for commercial flight test applications provides a real-world example of what is currently achievable.
    • EVALUATING IEEE 1588 IN A HOMOGENOUS SWITCHED NETWORK TEST ARTICLE SEGMENT

      Wilmot, Sinbad; Corry, Diarmuid; ACRA CONTROL INC (International Foundation for Telemetering, 2007-10)
      At the 2007 iNet Technology Demonstrator multiple vendors are asked to participate to develop and evaluate protocols for time synchronization, configuration identification and heterogeneous data packet transfer. The iNet initiative from RCC is aimed at focusing and collating telemetry network developments within the wider sphere of commercial and military network developments. The KAM-500 is an inherently networked data-acquisition system offering seamless gateways to many heterogeneous data sources, such as different sensor devices, avionics-busses, networks and video sources. This paper offers insights into the impact of traffic and network configuration on the performance of heterogeneous data acquisition in a homogenous-switched network based a 1588 enabled controller module.
    • PERFORMANCE CHARACTERIZATION OF MULTI-BAND ANTENNAS FOR AERONAUTICAL TELEMETRY

      Temple, Kip; Jefferis, Robert; Selbrede, Robert; Edwards Air Force Base (International Foundation for Telemetering, 2007-10)
      This paper baselines the performance of common, single band telemetry blade antennas in two telemetry bands and compares that performance to two very differing multi-band antenna designs. A description of each antenna is presented followed by flight testing results and conclusions. Results are in the form of received signal strength versus geographic location, derived in-flight antenna patterns, link availability, and bit error analysis.
    • 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.
    • BENEFITS AND TECHNIQUES FOR INCREASED POWER EFFICIENCY IN MODERN TELEMETRY TRANSMITTERS

      Bozarth, Don; Horcher, Greg; L-3 Communications (International Foundation for Telemetering, 2007-10)
      With recent developments in telemetry transmitter technologies, significantly greater DC to RF power efficiencies can be achieved. These new high efficiency transmitter designs may impact overall system design trade-offs by reducing the system size and weight requirements for batteries, heat sinks, and cabling. Furthermore, these fully DC isolated, next generation ARTM Tier 0, I and II enabled devices offer unique options to the platform designer in EMI/EMC control and system design. Advanced manufacturing techniques coupled with adaptive microprocessor control promises enhanced functionality, improved performance and reduced unit costs. The paper presents the performance of a new, high efficiency, telemetry transmitter topology and the possible system benefits involved with the application of this advanced transmitter technology within modern and legacy telemetry platforms. Specific sub-assembly circuit design techniques will be discussed and compared with prior design approaches.
    • 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.
    • GPS RADIOSONDE: MIGHTY MIDGET OF THE MODERN RANGE

      May, Linda R.; Honeywell Technology Solutions, Inc. (International Foundation for Telemetering, 2007-10)
      Wallops Flight Facility is NASA’s principal site for management and implementation of suborbital research programs. Recently, WFF resumed its successful satellite-launching history without sacrificing its culture of being low-cost and responsive. Part of what made this possible is the GPS radiosonde. During recent successful Minotaur I launches, this tiny instrument provided upper-air observations that were used in six categories of analysis necessary for such launches: toxics, blast, winds aloft, debris, weather and forecasting, and post-flight. In addition, the GPS radiosonde has reduced costs associated with Wind Weighting at Wallops, and is used in numerous range research projects.
    • TELEMETRY TRANSCEIVER DESIGN USING BOC SIGNAL

      Dongkai, Yang; Li, Du; Qishan, Zhang; Beihang University (International Foundation for Telemetering, 2007-10)
      This paper focuses on the transceiver design using BOC signal in the telemetry field, including the transmitter and receiver. The transmitter is similar as that using BPSK except from the sub-carrier modulation. But the receiver design is totally different because the BOC signal has different performance. The acquisition methods of BOC signal have been discussed such as the single-side BPSK-like, double-sides BPSK-like and hybrid processing methods, which can restrain side-peak and eliminate ambiguities. The three acquisition process principles and their performances include arithmetic complexity are described, compared and simulated using MATLAB.