Walter, Patrick L.; Texas Christian University; Endevco (International Foundation for Telemetering, 1998-10)
      Acquiring shock and vibration data from flight vehicles through rf telemetry links has numerous associated challenges. Yet, these measurements are important to establish environmental specifications to provide a basis for system or component design and testing. The principal limitation in acquiring these measurements is the frequency bandwidth available for data transmission. This limited bandwidth is often responsible for invalid data being accepted as valid. This work provides a brief review of time and frequency division multiplexing to identify the potential error contributors to shock and vibration measurements. Its focus is on the design of acceleration measurement systems to eliminate these errors and optimize individual measurement channel performance.

      Jerome, Chris; Johnson, Edward; Sittler, Arthur; Wainwright, Ross; Voss Scientific; Air Force Research Laboratory (International Foundation for Telemetering, 1998-10)
      The Space Sensing & Vehicle Control Branch of the Air Force Research Laboratory and Voss Scientific, Albuquerque, NM, are developing an advanced PC and COTS-based satellite telemetry processing, analysis and display system known as the PC-Satellite Telemetry Server (PC-STS). This program grew out of a need to develop less expensive, more capable, more flexible, and expandable solutions to the satellite telemetry analysis requirements of the Air Force. Any new system must employ industry standard, open architecture, network and database protocols allowing for easy growth and migration to new technologies, as they become available. Thus, the PC-STS will run on standard personal computers and the Windows NT operating system. The focus of this work and this paper is the Telemetry Server component, and in particular, the custom-built decommutation board. The decommution board will be capable of processing frame formatted and CCSDS packet telemetry. It will be capable of fully decommutating telemetry data, converting raw data to engineering units, and providing this data to the Telemetry Server host. Time tagged engineering units or minor frames of telemetry will be transmitted to the Telemetry Server processor via on-board memory buffers. The decom board uses the PCI bus, programmable DSPs, considerable on-board memory, and a SCSI bus for local archiving. This paper presents the general architecture of the PC-STS, and discusses specific design considerations. These include trade-offs made during the design of the board’s hardware and software, operational specifications, and graphical user interfaces to program, monitor, and control the board.

      Berg, Dale E.; Robertson, Perry J.; Sandia National Laboratories (International Foundation for Telemetering, 1998-10)
      Researchers at the National Wind Technology Center have identified a need to acquire data on the rotor of an operating wind turbine at precisely the same time as other data is acquired on the ground or a non-rotating part of the wind turbine. The researchers will analyze that combined data with statistical and correlation techniques to clearly establish phase information and loading paths and insights into the structural loading of wind turbines. A data acquisition unit has been developed to acquire the data from the rotating system at precise universal times specified by the user. The unit utilizes commercial data acquisition hardware, spread-spectrum radio modems, and a Global Positioning System receiver; and a custom-built programmable logic device. A prototype of the system is now operational, and initial field deployment is anticipated this summer.

      Rohre, Stuart M.; The University of Texas at Austin (International Foundation for Telemetering, 1998-10)
      A novel concept using the cockpit voice recorder (CVR) as a structural vibration recording device, to aid in structural health monitoring of commercial and military aircraft, is outlined. The unused cables in the CVR wiring harness act as “latent transducers” that respond to structural vibrations, generating vibration signals, which the CVR records. Postprocessing of such data can provide clues to problem areas or changes in the signature of the aircraft. The standards which the CVR must meet to qualify as a instrumentation-quality recorder are discussed and the steps required to assure compliance are outlined.

      Bracht, Roger; Dimsdle, Jeff; Rich, Dave; Smith, Frank; Los Alamos National Laboratory; AlliedSignal Federal Manufacturing & Technologies (International Foundation for Telemetering, 1998-10)
      High explosive radio telemetry (HERT) is a project that is being developed jointly by Los Alamos National Laboratory and AlliedSignal FM&T. The ultimate goal is to develop a small, modular telemetry system capable of high-speed detection of explosive events, with an accuracy on the order of 10 nanoseconds. The reliable telemetry of this data, from a high-speed missile trajectory, is a very challenging opportunity. All captured data must be transmitted in less than 20 microseconds of time duration. This requires a high bits/Hertz microwave telemetry modulation code to insure transmission of the data within the limited time interval available.

      Bracht, Roger; Los Alamos National laboratory (International Foundation for Telemetering, 1998-10)
      Remote, high speed, high explosive wave front monitoring requires very high bandwidth telemetry to allow transmission of diagnostic data before the explosion destroys the sensor system itself. The main motivation for this study is that no known existing implementation of this sort has been applied to realistic weapons environments. These facts have prompted the research and gathering of data that can be used to extrapolate towards finding the best modulation method for this application. In addition to research of similar existing analysis and testing operations, data was recently captured from a Joint Test Assembly (JTA) Air Launched Cruise Missile (ALCM) flight.
    • Range Communications System Using Asynchronous Transfer Mode (ATM)

      Eslinger, Brian; McCombe, Joleen; TYBRIN Corp.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      As aircraft become more complex and require more resources over larger areas, the challenge of the test ranges is to provide economical solutions to move telemetry data from the test article to the data processing facility. Edwards AFB is in the process of upgrading the ground transmission facilities to transport data including telemetry using Asynchronous Transfer Mode (ATM). This paper documents the challenge of supporting telemetry over ATM, different approaches that are available, the benefits of using ATM, and discussion of candidate hardware options. The effort at Edwards include the linking of the major range facilities over a fiber optic backbone and links to other major test ranges in the Southwest Range Complex via microwave. The fiber optic backbone is expected to be OC-12c (622 Mbps) ATM supporting new capabilities as well as all of the legacy systems. The backbone system will be designed so that migration to OC-48 is possible without service disruption. The microwave links are multiple DS-3 capable. Some of these DS-3s may support legacy systems, but the ability to link ranges using ATM is expected simultaneously.

      Thomas, D. Paul; Lockheed Martin Vought Systems (International Foundation for Telemetering, 1998-10)
      The Range Commanders Council "Flight Termination Systems Commonality Standard," RCC 319-92, has been written with the noble goal of providing "common design, test, and documentation requirements for Flight Termination Systems (FTS)." As is often the case with standards of any kind, the devil is in the details! The Army TACMS (ATACMS) Block II Flight Termination/Telemetry System design has been significantly affected by the constraints imposed by RCC 319-92 as well as by Lockheed Martin Vought Systems customers' interpretations of those constraints and requirements. Important system elements are discussed along with some of the engineering decisions made to achieve compliance and the rationale behind those decisions. It is hoped that this monograph will acquaint potential users of RCC 319-92 with some of the issues involved in achieving compliance.

      Ng, Sunny; Wei, Mei Y.; Somes, Austin; Aoyagi, Mich; Leung, Joe; National Aeronautics and Space Administration; Recom Technologies (International Foundation for Telemetering, 1998-10)
      This paper describes a distributed network client-server system developed for researchers to perform real-time or near-real-time analyses on ensembles of telemetry data previously done in post-flight. The client-server software approach provides extensible computing and real-time access to data at multiple remote client sites. Researchers at remote sites can share similar information as those at the test site. The system has been used successfully in numerous commercial, academic and NASA wide aircraft flight testing.

      Billings, Don; Wei, Mei; Leung, Joseph; Aoyagi, Michio; Shigemoto, Fred; Honeyman, Rob; NASA; Recom Technologies (International Foundation for Telemetering, 1998-10)
      Although PCM/TDM framed data is one of the most prevalent formats handled by flight test ranges, it is often required to acquire and process other types. Examples of such non-standard data types are radar position information and meteorological data from both ground based and radiosonde systems. To facilitate the process and management of such non-standard data types, a micro-processor based system was developed to acquire and transform them into a standard PCM/TDM data frame. This obviated the expense of developing additional special software and hardware to handle such non-standard data types.
    • Real-Time Telemetry Network

      Chalfant, Timothy A.; Gurr, Richard; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      We need to begin to define what the future of point-to-point telemetry will be in the new world of wireless communications, increasing bandwidth requirements, the integration of test and training, and modeling and simulation (M&S) interacting with open air ranges. The Advanced Range Telemetry Program will introduce several new technologies to the telemetry community over the next several years, how will we use and build on them for the future? What kind of architecture will we need to be able to interact with the M&S and Training communities? How do we create that architecture and to what use would it be put by a test program? The answer, we believe, is to build the equivalent of a network in the sky. An extension of the Internet, in simplistic terms. The system under test (SUT), or the systems in training would become nodes of a large interactive network. Instead of the SUT being treated as something outside the sphere of control for the range, the SUTs onboard instrumentation systems would become an integral part of the greater range complex. This paper will address what the architecture of a real-time telemetry network might look like and how it could be implemented within the telemetry community.

      Drews, Michael E.; Forman, Douglas A.; Baker, Damon M.; Khazoyan, Louis B.; Viazzo, Danilo; Octant Technologies, Inc.; Boeing Information; Integrated Systems, Inc. (International Foundation for Telemetering, 1998-10)
      A real-time telemetry simulator of the IUS spacecraft has recently entered operation to train Flight Control Teams for the 1aunch of the AXAF telescope from the Shuttle. The simulator has proven to be a successful higher fidelity implementation of its predecessor, while affirming the rapid development methodology used in its design. Although composed of COTS hardware and software, the system simulates the full breadth of the mission: Launch, Pre-Deployment-Checkout, Burn Sequence, and AXAF/IUS separation. Realism is increased through patching the system into the operations facility to simulate IUS telemetry, Shuttle telemetry, and the Tracking Station link (commands and status message).

      Kujiraoka, Scott R.; De Vries, James M.; Naval Air Warfare Center (International Foundation for Telemetering, 1998-10)
      The available space for the mounting of antennas on missiles and airborne targets is very limited. The vehicle integrator is constantly striving for smaller antenna apertures while requiring increased performance. Microstrip antennas with moderate dielectric loading have been successfully utilized in the past to meet these requirements. With the advent of high dielectric substrate materials, the designer now has the option of further reducing the size of the antenna while preserving the most desirable performance attributes. An example of the size reduction achievable with the new substrate materials is presented along with performance characteristics.
    • Reed-Solomon Coding as a Multipath Fading Countermeasure for PCM/FM Aeronautical Telemetry

      Rice, Michael D.; Friend, Daniel H.; Brigham Young University (International Foundation for Telemetering, 1998-10)
      This paper evaluates the use of Reed-Solomon error correcting codes as a countermeasure for the bursty errors caused by multipath fading seen in aeronautical telemetry channels. The tradeoff between code rate and interleaving depth is analyzed and an equation for predicting the code rate given a fixed burst length and interleaving depth is presented. Close agreement is found between predictions made by this equation and simulated results.

      Willis, James; L-3 Communications (International Foundation for Telemetering, 1998-10)
      Universal acceptance of the Windows NT operating system has made utilization of the personal computer (PC) platform for critical space operations a reality. The software attributes of the operating system allow PC products to attain the reliability necessary for secure control of on-orbit assets. Not only is the software more reliable, it supports better networking interfaces at higher speeds. The software upgrades that the Microsoft Corporation generates on a regular basis allow PCs to offer capabilities previously available only with UNIX-based solutions. As technology matures, PCs will operate faster, offer more graphical user interfaces, and give customers a lower cost versus performance choice. These reasons, and others to be discussed further, clearly demonstrate that PCs will soon take their place at the forefront of mission-critical ground station applications.

      Briggs, James R.; Youssef, Ahmed H.; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      Optical trackers are often used at the Air Force Flight Test Center (AFFTC) and at other Department of Defense (DoD) ranges to collect video and trajectory data for real-time display and postflight processing. When optical trackers are used in remote areas, pointing data from radar is utilized to enable the trackers to initially acquire targets. To enable the trackers to use radar-pointing data, offsets to true north must first be known. This offset is taken into account given the current position of the optical tracker. During postflight processing, when determining the trajectory of the target, the offsets are also taken into account to produce an accurate trajectory solution. Current methods of determining offsets to true north are time consuming and involve a lot of guesswork. Typically, a map and a known landmark are used to determine the offsets to true north. Another method is to look for the North Star (Polaris) and input an estimated offset. This paper will describe an inexpensive, stand-alone system that utilizes the Global Positioning System (GPS) to determine these offsets. This device may be modified and integrated with other systems that may need to point accurately. For example, a gun barrel on a tank may need to point accurately to within a degree. This device may also be used to accurately position telemetry antennas.
    • Selling Telemetry Data Over the Internet Using SET

      Kalibjian, Jeffrey R.; CounterSign Software, Inc. (International Foundation for Telemetering, 1998-10)
      Over the past two years the design and implementation of secure Internet based data sharing tools which could enable geographically remote contractor teams to access flight and test telemetry data securely over the Internet were presented [1] [2]. Key technologies facilitating these capabilities were the Hypertext Transfer (HTTP) protocol , the Secure Sockets Layer (SSL) protocol, and the Secure Multipurpose Internet Mail Extension (S/MIME) specification . This year we discuss utilizing the Secure Electronic Transaction (SET) specification in tandem with HTTP, SSL, and S/MIME to deploy a system for securely selling telemetry data over the Internet.

      O’Cull, Douglas; Microdyne Corporation (International Foundation for Telemetering, 1998-10)
      This paper discusses modifications made to a commercial-off-the-shelf (COTS) signal generator that aids acquisition of low earth orbit (LEO) satellites. The modification compensates for the Doppler Frequency offset that commonly affects acquisition of LEO satellites. This allows the user to use a COTS signal generator for the uplink exciter. User programmable features have been added to the signal generator, which compensates for the Doppler Shift.
    • So You Think Tape is Dead

      Smith, Darren C.; Tenderholt, Dean; Naval Air Warfare Center - Weapons Division; Edwards Air Force Base (International Foundation for Telemetering, 1998-10)
      The times that we live in offers the most advanced pace of technology development ever known to the world, and it is getting faster. A large part of commercial computer technology development is based on increased size and decreased cost of memory devices, from which the instrumentation community can derive great benefit through the development of solid state systems. The procurement cost of new solid state systems utilizing increased memory capability makes the temptation to move to this technology unavoidable. There are, however, some issues that need to be discussed which go beyond procurement costs and involve operational and life cycle considerations.

      O’Donnell, John; AYDIN Telemetry (International Foundation for Telemetering, 1998-10)
      There are well-known advantages in using pseudo-random sequences for testing of data communication links. The sequences, also called pseudo-noise (PN) sequences, approximate random data very well, especially for sequences thousands of bits long. They are easy to generate and are widely used for bit error rate testing because it is easy to synchronize a slave pattern generator to a received PN stream for bit-by-bit comparison. There are other aspects of PN sequences, however, that are not as widely known or applied. This paper points out how some of the less familiar characteristics of PN sequences can be put to practical use in the design of a Digital Test Set and other specialbuilt test equipment used for checkout of the EOS AM-1 Space Data Receiver. The paper also shows how knowledge of these PN sequence characteristics can simplify troubleshooting the digital sections in the Space Data Receiver. Finally, the paper addresses the sufficiency of PN data testing in characterizing the performance of a receiver/data recovery system.