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.

      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.

      Pérez-Falcón, Tony; Kolar, Ray; Reliable System Services Corporation; Atlantic Coast Technologies, Inc. (International Foundation for Telemetering, 2002-10)
      This paper presents a Flight Safety System (FSS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of flying Over-the-Horizon (OTH) and outside test range airspace. Expanded uses beyond flight safety, such as UAV Air Traffic Control, are considered also. This system satisfies the operational requirement for a Hazard Control Communication Channel as well as providing a reverse communications channel to provide Safety Critical Information to the Range Safety Officer (RSO). Upon examining 60 communications candidates, IRIDIUM accessed through a Data Distribution Network (DDN), with ARINC being a potential service provider, is recommended.
    • International Telemetering Conference Proceedings, Volume 38 (2002)

      International Foundation for Telemetering, 2002-10

      Rash, James; Hogie, Keith; Casasanta, Ralph; NASA; Computer Sciences Corporation (International Foundation for Telemetering, 2002-10)
      Ongoing work at National Aeronautics and Space Administration Goddard Space Flight Center (NASA/GSFC), seeks to apply standard Internet applications and protocols to meet the technology challenge of future satellite missions. Internet protocols and technologies are under study as a future means to provide seamless dynamic communication among heterogeneous instruments, spacecraft, ground stations, constellations of spacecraft, and science investigators. The primary objective is to design and demonstrate in the laboratory the automated end-to-end transport of files in a simulated dynamic space environment using off-the-shelf, low-cost, commodity-level standard applications and protocols. The demonstrated functions and capabilities will become increasingly significant in the years to come as both earth and space science missions fly more sensors and the present labor-intensive, mission-specific techniques for processing and routing data become prohibitively. This paper describes how an IP-based communication architecture can support all existing operations concepts and how it will enable some new and complex communication and science concepts. The authors identify specific end-to-end data flows from the instruments to the control centers and scientists, and then describe how each data flow can be supported using standard Internet protocols and applications. The scenarios include normal data downlink and command uplink as well as recovery scenarios for both onboard and ground failures. The scenarios are based on an Earth orbiting spacecraft with downlink data rates from 300 Kbps to 4 Mbps. Included examples are based on designs currently being investigated for potential use by the Global Precipitation Measurement (GPM) mission.

      Hill, Terrance; Geoghegan, Mark; Nova Engineering Inc. (International Foundation for Telemetering, 2002-10)
      It is widely recognized that telemetry channels, particularly airborne channels, are afflicted by multipath propagation effects. It has also been shown that adaptive equalization can be highly effective in mitigating these effects. However, numerous other factors influence the behavior of adaptive equalization, and the type of modulation employed is certainly one of these factors. This is particularly true on modulations which exhibit different operating bandwidths. In this paper, we will examine the effect multipath and adaptive equalization for three modulation techniques which are either already in use, or have been proposed, for airborne telemetry.

      James, William G., Jr.; Eglin Air Force Base (International Foundation for Telemetering, 2002-10)
      The Central Control Facility at Eglin Air Force Base has acquired full intellectual rights to a single board telemetry card with device driver and test software. This card has an integrated IRIG 106 PCM decommutator, IRIG time clock and minimal PCM simulator capability using the latest in Field Programmable Gate Array technology. Eglin will offer this capability to the telemetry community as both open source hardware and software and solicit partnerships with both government and private industry for both open source and closed source for-profit products.

      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.
    • 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.

      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.
    • Making All The Data Available Some Of The Time In Very Large Telemetry Volume Space Applications

      Cook, David B. (International Foundation for Telemetering, 2002-10)
      What do you do when your downlink telemetry needs outstrip your downlink bandwidth capability? The telemetry needed to support construction and operation of the largest, most complex engineering project ever undertaken, the International Space Station (ISS), already requires utilization of the full capacity of the downlink S-band capacity, yet there are additional systems and capabilities still to be added by NASA and the International Partners. The ISS Command and Telemetry Team has developed a method of swapping packets of telemetry that are intended for special operations, while simultaneously sending essential systems telemetry and less critical telemetry that is needed on a continuous basis. To support this attempt to “make available all of the data at least some of the time” the team developed concepts for grouping telemetry into families that would always be selected as a group and then created a set of metadata associated with these groups. This metadata is pre-defined to support automated selection and scrubbing of telemetry to correspond to major upgrades in the command and control software for the ISS. The new process will at least double the effective S-band downlink bandwidth. It will also provide automated selection, scrubbing, reporting and verification of telemetry selections.

      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.

      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.

      Fink, U.; Schooley, L. C.; Hudor, A.; Eatchel, A. L.; Fevig, R.; Cooper, C.; Gruenenfelder, J.; Wallace, J.; University of Arizona (International Foundation for Telemetering, 2002-10)
      A telemetry system has been developed at the University of Arizona to serve as a baseline for future CubeSat designs. Two satellites are scheduled for launch in November of 2002. One features a beacon that operates autonomously of all but the power system and can independently deploy the antennas. The other will test the performance of new semiconductor devices in low earth orbit. Sensors will monitor voltages, currents (from which attitude and tumble rate can be derived), received signal strength and a distribution of temperatures. The CubeSat’s architecture, operating system, sensors, telemetry format and link budget are discussed.

      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.
    • 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.

      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.

      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.

      K/Bidy, Gilles; L-3 Communications (International Foundation for Telemetering, 2002-10)
      Because of an ever-increasing need for performance and high predictability in modern real-time telemetry systems, the Java programming language is typically not considered a viable option for embedded software development. Nevertheless, the Java platform provides many features that can easily be applied to embedded telemetry systems that other development platforms cannot match. But obviously, there are pitfalls to be aware of. This paper will present an alternative solution to address today’s problems in real-time telemetry systems and will cover the following topics: • Java development platforms for the embedded world • Impact on software portability and reusability • Performance and optimization techniques • Direct access to hardware devices • Memory management and garbage collection • Network-centric component-oriented architecture • Real-time examples from past experience • Future developments