Now showing items 21-40 of 93

    • 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.

      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.

      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.

      Archibald, James K.; Beard, Randal W.; Olson, Steven A. R.; Dawson, Chad S.; Jacobson, Jared; Brigham Young University (International Foundation for Telemetering, 2002-10)
      This paper describes the construction of an autonomous soccer playing robot as part of a senior design project at Brigham Young University. Each participating team designed and built a robot to compete in an annual tournament. To accomplish this, each team had access to images received from a camera placed above a soccer field. The creation of image processing and artificial intelligence software were required to allow the robot to perform against other robots in a one-on-one competition. Each participating team was given resources to accomplish this project. This paper contains a summary of the experiences gained by team members and also a description of the key components created for the robot named Prometheus to compete and win the annual tournament.

      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.

      Juan, Lu; Qing, Chang; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      With the purpose of testing the performance of GPS receivers, a GPS signal simulator is needed that can emulate the real GPS signals under all kinds of the conditions. This paper analyzes the single channel and multi-channel GPS signals’ characters in time domain and frequency domain, and discusses a mathematic model of the twelve-channel GPS simulator. In order to reduce the difficulties of the hardware design, this model is designed to provide the IF signal directly by applying the idea of “software radio”and the theory of interpolation. Simulation results with SystemView software demonstrate the feasibility of the system scheme. A practical hardware design of this system is described.
    • 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.

      Meyer, Steven J.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      The Joint Advanced Missile Instrumentation (JAMI) program is developing a Time, Space, and Position Information (TSPI) unit for high dynamic missile platforms by employing the use of Global Position System (GPS) and inertial sensors. The GPS data is uncoupled from the inertial data. The output of the JAMI TSPI unit follows the packet telemetry protocol and is called the TSPI unit message structure (TUMS). The packet format allows the data stream to stand on its own, be integrated into a packet telemetry system or be an asynchronous data channel in a PCM data stream. On the ground, the JAMI data processor (JDP) Kalman filters the GPS and inertial data to provide a real time TSPI solution to the ranges for display. This paper gives an overview of the message format, the timing relationships between the GPS data and inertial data, and how TUMS is to be handled by the telemetry receiving site to hand it off to the JDP.

      Meyer, Steven J.; Kujiraoka, Scott R.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      The Joint Advanced Missile Instrumentation (JAMI) program is integrating Global Positioning System (GPS) technology into missile telemetry systems. The weakest link appears to be the GPS antenna. The antenna on a missile is required to be flush mounted for aerodynamic reasons. Due to the missile’s tendency to roll, the antenna needs to be a multi-element omnidirectional antenna array. Therefore an antenna used on missiles is a wrap-around antenna since it will meet the flush mount and rolling requirements by giving omnidirectional coverage. JAMI has used readily available techniques for designing wrap-around telemetry antennas to develop a GPS wrap-around antenna and has discovered a major problem. The Phase Center of a wrap-around antenna tends to be a surface, not a point, and not necessarily at the centerline of the missile body. GPS measurements have been conducted to determine the Phase Center of the antenna. When the Phase Center is large, the GPS receiver perceives it as multipath and integer ambiguities cannot be resolved. This paper addresses the problems that have been uncovered and outlines the steps that are planned to resolve them.

      Powell, Dave; Scofield, Don; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2002-10)
      Joint Advanced Missile Instrumentation (JAMI), a Central Test and Evaluation Investment Program (CTEIP) initiative, is developing advanced telemetry system components that can be used in an integrated instrumentation package for tri-service small missile test and training applications. JAMI demonstrated significant improvement in the performance of low-cost Global Positioning System (GPS) based Time-Space-Position Information (TSPI) tracking hardware that can be used for world-wide test and training. Acquisition times of less than 3 seconds from a cold start and tracking dynamics to over 60 Gs were demonstrated. The design of a programmable Flight Termination Safe and Arm device has been completed. This paper discusses the progress of the program during the past year and the efforts planned for fiscal year 2002. High dynamic testing results of GPS and Inertial measurement Unit (IMU) devices and problems encountered are discussed.

      Andrews, M. S.; TRW Radio Systems (International Foundation for Telemetering, 2002-10)
      The scope of the problem with generalized linear power amplifiers is herein addressed. In this paper, after an introduction to the problem of linearity and power amplifiers is addressed, a survey of various design issues from PA topology, materials, and linearization electronics is given. Following this, a look toward future work in this very active area of current research is also offered.

      Chapin, John; Shah, Alok; Vanu, Inc. (International Foundation for Telemetering, 2002-10)
      This paper provides an overview of software radio and its current state in the industry. Software radio is a technology in which all of the waveform processing, including the physical layer, of a wireless device moves into software. If designed properly, this approach leads to dramatically improved device flexibility, software portability, and reduced development costs. Of course, such a technology brings with it numerous challenges, from hardware components to power constraints to the regulatory environment.
    • An IF Sampling Digital Receiver Implementation for Space-based Command and Telemetry Applications

      Maples, Bruce W.; Fix, Keith A.; CMC Electronics Cincinnati (International Foundation for Telemetering, 2002-10)
      This paper describes an approach to the implementation of an IF sampling digital receiver for low data rate command and telemetry applications in the NASA Goddard Spaceflight Tracking and Data Network (STDN) and Air Force Space-Ground Link System (SGLS). The digital design is targeted for an FPGA-based implementation and was written entirely in VHDL. Several size and clock reduction techniques are described which were utilized due to limited gate-array resources and power. The system-level design architecture is described followed by a discussion of algorithms and performance of critical stages in the receiver chain. Bit error performance of the prototype receiver is also presented. Finally, although this design is specifically targeted for a narrowband command and telemetry application, the methodology forms the basis of a configurable receiver for higher data rate applications.

      Brierley, Scott; Boeing Company (International Foundation for Telemetering, 2002-10)
      Using a network-based telemetry system places additional requirements on the Radio Frequency (RF) link. Limitations imposed by this link must be considered in advance when designing a network-based telemetry system.

      Grebe, David L.; Apogee Labs Inc. (International Foundation for Telemetering, 2002-10)
      The role of recorders in telemetry applications has undergone many changes throughout the years. We’ve seen the evolution from multi-track tape to disk to solid state technologies, both for airborne and ground based equipment. Data acquisition and collection system design has changed as well and a recent trend in airborne is to merge acquisition and recording. On the ground, increased decentralization of data collection and processing has generated the requirement to provide backup storage to protect against communication circuit outages. This paper explores the trend to adopt network based data acquisition, collection, and distribution systems for telemetry applications and the impact on recording techniques and equipment. It shows that in this emerging approach the recorder returns to its root mission of attempting to provide the fastest, largest capacity for the least amount of investment. In a network based architecture the recorder need only accept and reproduce data operating independently from the acquisition process.

      Eccles, Lee H.; Boeing Commercial Airplanes (International Foundation for Telemetering, 2002-10)
      Transducers have traditionally been incorporated into data systems by connecting the transducer to a signal conditioner that is then connected to a multiplexer with an Analog-to-Digital Converter (ADC). The signal conditioning, multiplexer and the ADC are usually included within the same assembly that is called a Data Acquisition Unit (DAU) or an encoder. A network centric data system allows the same architecture to be used if the interface to the encoder is changed to be a network interface. However, a network centric architecture allows other options as well. The signal conditioning and ADC can be included within the same package as the transducer and the assembly can be interfaced to the network. When this is combined with the processing capability now available, a whole new range of possibilities present themselves. The transducer can now be digitally processed to provide a linear output, it can be converted to Engineering Units, digitally filtered or have a host of other functions performed within the housing that contains the transducer. However, the network centric approach does not produce these advantages without some disadvantages. The major problem that needs to be solved is how we time stamp the data. With the encoder we could time stamp the PCM frame and be able to determine the time that a sample was taken from that information. Even in systems that convert the encoder to have a network interface, the time stamp needs to be affixed to the data in the encoder. With a network centric approach, the sample can be taken in the transducer and how to time stamp it becomes a real problem. This is a problem that must be considered at the system level. Some method of making time available at a low enough level in the system to allow transducer outputs to be time stamped is either a network issue or it requires a separate interface.

      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.

      Jones, Sid; Naval Air Systems Team (International Foundation for Telemetering, 2002-10)
      There are many network standards in the commercial market today. The layered concept works so well, a developer can implement exactly the capability they desire through careful selection of standards and protocols. This brings up an interesting question of where we draw the line between standardizing on a single implementation and allowing the flexibility of all there is to offer? There are valid arguments for both sides. The telemetry community cannot afford to let this question fall through the cracks. We have the chance to identify what we need to do and how we should do it for both the specific application and the overall system.

      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.

      Boying, Lu; Jun, Zhang; Shuhui, Nie; Xinjian, Huang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      This paper presents the basic concept, construction principle and implementation work for the Automatic Dependent Surveillance (ADS) system. As a part of ADS system, the ADS message processing system based on PC computer was given more attention. Furthermore, the paper introduces the ADS trial status and points out that the ADS implementation will bring tremendous economical and social efficiency.