• A 400 Mbps High Density Digital Recording System

      Kibalo, Tom; Miles, Ben; Alliant Techsystems Inc. (International Foundation for Telemetering, 1995-11)
      A highly versatile 400 Mbps High Density Digital Recording System for telemetry and GPS downlink acquisition at Vandenberg AFB, California is discussed. The system supports 24 channels of data acquisition, is realized using entirely COTS components, and achieves full IRIG compatibility without any compromise in the desired system performance and operation.

      Dowling, Jason; Welling, John; Aerosys, Loral; Nanzetta, Kathy; Bennett, Toby; Shi, Jeff; NASA (International Foundation for Telemetering, 1995-11)
      NASA’s use of high bandwidth packetized Consultative Committee for Space Data Systems (CCSDS) telemetry in future missions presents a great challenge to ground data system developers. These missions, including the Earth Observing System (EOS), call for high data rate interfaces and small packet sizes. Because each packet requires a similar amount of protocol processing, high data rates and small packet sizes dramatically increase the real-time workload on ground packet processing systems. NASA’s Goddard Space Flight Center has been developing packet processing subsystems for more than twelve years. Implementations of these subsystems have ranged from mini-computers to single-card VLSI multiprocessor subsystems. The latter subsystem, known as the VLSI Packet Processor, was first deployed in 1991 for use in support of the Solar Anomalous & Magnetospheric Particle Explorer (SAMPEX) mission. An upgraded version of this VMEBus card, first deployed for Space Station flight hardware verification, has demonstrated sustained throughput of up to 50 Megabits per second and 15,000 packets per second. Future space missions including EOS will require significantly higher data and packet rate performance. A new approach to packet processing is under development that will not only increase performance levels by at least a factor of six but also reduce subsystem replication costs by a factor of five. This paper will discuss the development of a next generation packet processing subsystem and the architectural changes necessary to achieve a thirty-fold improvement in the performance/price of real-time packet processing.
    • An ACTS Mobile Receiver Simulation

      Mott, Brian J.; Wise, Kevin D.; Brigham Young University (International Foundation for Telemetering, 1995-11)
      The continuing demand for mobile communication and the growing congestion of currently assigned frequency bands has precipitated the development of K/Ka band mobile-satellite technology. The Jet Propulsions Lab (JPL), using the Advanced Communications Technology Satellite (ACTS), has conducted prototype testing of a K/Ka band mobile-satellite link. The JPL system uses a narrow beam antenna which tracks the satellite signal. As the JPL vehicle experienced changes in yaw, pitch, and roll, the antenna experienced a pointing error. A model to describe the power losses caused by pointing error is developed. This model shows a received power loss on the order of 2.0 dB.

      Chesney, James R.; Bakos, Roger; TSI TelSys, Inc. (International Foundation for Telemetering, 1995-11)
      The remote sensing industry is experiencing an unprecedented rush of activity to deploy commercial and scientific satellites. NASA and its international partners are leading the scientific charge with The Earth Observation System (EOS) and the International Space Station Alpha (ISSA). Additionally, there are at least ten countries promoting scientific/commercial remote sensing satellite programs. Within the United States, commercial initiatives are being under taken by a number of companies including Computer Technology Associates, Inc., EarthWatch, Inc., Space Imaging, Inc., Orbital Imaging Corporation and TRW, Inc. This activity is due to factors including: technological advances which have lead to significant reductions in the costs to build and deploy satellites; an awareness of the importance of understanding human impact on the ecosystem; and a desire to collect and sell data some believe will be worth $1.5 billion (USD) per year within five years. The success and usefulness of these initiatives, both scientific and commercial, depends largely on the ease and cost of providing remotely sensed data to value added resellers and end-users. A number of these spacecraft will provide an interface directly to users. To provide these data to the largest possible user base, ground station equipment must be affordable and the data must be distributed in a timely manner (meaning seconds or minutes, not days) over commercial network and communications equipment. TSI TelSys, Inc. is developing ground station equipment that will perform both traditional telemetry processing and the bridging and routing functions required to seamlessly interface commercial local- and wide-area networks and satellite communication networks. These products are based on Very Large Scale Integration (VLSI) components and pipelined, multi-processing architectures. This paper describes TelSys’ product family and its envisioned use within a ground station.
    • Airborne and Ground Data Processing Systems for the RAH-66 Comanche

      Cox, John R.; Sikorsky Aircraft Corporation (International Foundation for Telemetering, 1995-11)
      The RAH-66 Comanche flight test program requires a state of the art air vehicle and avionics data system consisting of: 1) An airborne, all digital multiplexing and recording system capable of combining digital streams at very high data rates; 2) The ability to record high speed avionics busses from the MEP (Mission Equipment Package) such as MIL-STD-1553B, HSDB (High Speed Data Bus,) PI (Processor Interconnect) Bus, DFN (Data Flow Network,) and TM (Test and Measurement Bus;) 3) A miniaturized, programmable, modular/distributed high speed PCM measurement system for 550 air vehicle measurements recorded on the Comanche Flight Test Aircraft and Propulsion System Test Bed; 4) an airborne digital multiplexing and recording system for recording a composite stream on an Ampex DCRsi tape recorder; 5) A high capacity ground data processing system using parallel processing computers for real time data compression; and 6) distributed analysis system using workstations for data processing with centralized disk storage.

      Hall, Richard C.; Wu, Doris I.; Boulder Microwave Technologies, Inc. (International Foundation for Telemetering, 1995-11)
      Conformal printed antennas of arbitrary shape are used for telemetry applications on high velocity vehicles due to their small size and light weight. The design of these antennas is difficult, however, since there are few accurate analytical models that take the effects of curvature into account. This paper discusses a computer aided design (CAD) tool for arbitrarily shaped printed antennas on cylindrical structures based on a rigorous analytical model. The tool is combined with a graphical user interface and can help antenna designers achieve close to optimal performance. An overview of the mathematical model is given here and the CAD tool is used to highlight the effects of curvature on printed antenna performance. Methods of obtaining circular polarization are reviewed.
    • An Analysis of Various Digital Filter Types for Use as Matched Pre-Sample Filters in Data Encoders

      Hicks, William T. (International Foundation for Telemetering, 1995-11)
      The need for precise gain and phase matching in multi-channel data sampling systems can result in very strict design requirements for presample or anti-aliasing filters. The traditional use of active RC-type filters is expensive, especially when performance requirements are tight and when operation over a wide environmental temperature range is required. New Digital Signal Processing (DSP) techniques have provided an opportunity for cost reduction and/or performance improvements in these types of applications. This paper summarizes the results of an evaluation of various digital filter types used as matched presample filters in data sampling systems.
    • The Application of GPS Technology to the Future Spacelift Range System (SLRS)

      Spellman, Marc; Harris Corporation (International Foundation for Telemetering, 1995-11)
      The Spacelift Range infrastructure of the United States Air Force will, over the next decade, experience a major modernization and upgrade. The goal of the Range Standardization and Automation (RSA) Program is to meet the requirements of range users and range safety in a more cost effective manner than is currently possible. One approach that will be considered in best achieving these goals is the further application of GPS technology to both the Eastern and Western Spacelift Ranges. Such an application can have a profound impact on the instrumentation segment of each range. Included within the instrumentation segment and clearly impacted, are both the metric tracking and telemetry subsystems. This paper considers the SLRS requirements that can be supported with GPS technology; the advantages and shortcomings of both GPS technology and alternative techniques; and provides suggestions as to an appropriate application of GPS technology to the SLRS.
    • Application of GPS to Hybrid Integrated Ranges and Simulations

      Van Wechel, R. J.; Jarrell, R. P.; Interstate Electronics Corp. (International Foundation for Telemetering, 1995-11)
      GPS user equipment has matured and is now available to support the use of live players in integrated ranges and simulations. P-code GPS provides true WGS-84 based coordinate information anywhere in the world at any time and to accuracies at the 5 ft (1s) level (demonstrated in high dynamic aircraft using differential P-code GPS). C/A code GPS shows lower accuracy and is especially vulnerable to multipath degradation over water. In supporting networked ranges with simulations, GPS is directly applicable to the dead reckoning requirements of the Distributed Interactive Simulation (DIS) community. DIS dead reckoning provides the capability of much reduced data rates in recovering TSPI information from platforms. The on-board state vector for an integrated GPS/Inertial Reference Unit provides accurate position, velocity and acceleration as well as attitude and attitude rate information so that dead reckoning thresholds can be both position and attitude driven. A simplified analysis is presented in the paper to derive dead reckoning update rates from the G loading levels of various player dynamics. Also, information is provided which results in word length requirements for GPS-based state vector information for transmission over minimum word length DIS Field Instrumentation Protocol Data Units (PDUs, which are the data block formats). The coordinate frame problem in use of GPS-based state vector information from fixed ranges is also addressed, showing that the use of a local geodetic frame is preferable to the use of an earth centered earth fixed frame, in that it is more efficient of network PDU word length.
    • BYU SAR: A Low Cost Compact Synthetic Aperture Radar

      Long, David G.; Jarrett, Bryan; Arnold, David V.; Cano, Jorge (International Foundation for Telemetering, 1995-11)
      Synthetic Aperture Radar (SAR) systems are typically very complex and expensive. They generate enormous quantities of data, requiring very high capacity data storage, transmission, and processing systems. We have developed an experimental SAR system with a very simple design which includes near-real-time onboard processing. This system is based on recent developments in low-cost, high-rate analog-to-digital (A/D) and digital-to-analog (D/A) data conversion systems. Most of the system is based on off-the-shelf components. A very simple RF subsystem is used. The system has been successfully operated from a moving surface vehicle and exhibits a range resolution of 2.5 m though this could be improved to 1.5 m at the expense of higher sidelobes. The four look azimuth resolution is 0.4 m. This paper describes the system as well as our plans for upgrading the system for aircraft operation and improved resolution.
    • A CCSDS Compatible High-Rate Telemetry Formatter for Space Application

      Barringer, Bruce O.; Orbital Science Corporation (International Foundation for Telemetering, 1995-11)
      OSC is presently developing a high-rate telemetry collection and formatting component for NASA's EOS-AM1 spacecraft. This device, called the Science Formatting Equipment, is capable of collecting data at aggregate rates exceeding 130 Mbps. The collected data is formatted into CCSDS compatible data structures, error coded, and then routed either to a downlink output or to a recording device at data rates up to 150 Mbps. This paper serves as a brief introduction to this component.
    • CCSDS in the Loral 550

      Sutton, Jerry; Taylor, Larry; Loral Test & Information System (International Foundation for Telemetering, 1995-11)
      The Consultative Committee on Space Data Systems (CCSDS) did not create a specification like the IRIG 106, but rather a recommendation [1-4]. That means that each country, community, and application is free to select subsets, adapt techniques, and even alter the structure to suit particular needs. This variability places new demands on a decommutation system. The implementation of the CCSDS Recommendation in the Loral 550 accommodates this "variability within a structure" by using a modular and adaptable collection of structured components. The result covers the two most popular versions of CCSDS: Conventional/Telecommand and the Advanced Orbital Systems (AOS) in both operational and test modes, and couples the CCSDS inputs and outputs to a host of other data format and processing options.

      Farmer, Mike; Culver, Randy; Loral Federal Services Corporation (International Foundation for Telemetering, 1995-11)
      Satellite operations have been inherently manpower intensive since they began over thirty years ago. Since manpower intensive equates to costs, this mode of operations cannot survive in light of government budget cuts and commercial profitability. Two factors are now key for both government and commercial satellite control centers: 1) systems must be highly automated to minimize the operations staff, and 2) these automated systems must be deployed and enhanced at a low cost. This paper describes the three principle challenges which arise in migrating from high-cost, manpower intensive satellite operations to low-cost, automated satellite operations and makes recommendations for solving them.

      Brown, Thomas R. Jr; Naval Air Warfare Center, Aircraft Division (International Foundation for Telemetering, 1995-11)
      The Department of Defense (DoD), through a Tri-Service Program Office, is developing the Common Airborne Instrumentation System (CAIS) to promote standardization, commonality, and interoperability among aircraft test instrumentation systems. The advent of CAIS will change how the DoD test community conducts business. The CAIS program will allow aircraft test and evaluation facilities to utilize common airborne systems, ground support equipment, and technical knowledge for airborne instrumentation systems. During the development of the CAIS, the Program Office will conduct a broad spectrum of tests: engineering design, acceptance, environmental qualification, system demonstration, and flight qualification. Each of these tests addresses specific aspects of the overall functional requirements and specifications. The use of test matrices enables the program office to insure each specific test covers the optimum requirements, and the combination of all testing efforts addresses the total system functional requirements.
    • Common Test and Training Range Architecture

      Pace, Richard; Walters, Charles E. (International Foundation for Telemetering, 1995-11)
      To address the concerns of a declining defense budget, duplicate range capabilities, and applications of new technologies, the Deputy Director, Test Facilities and Resources, Test, Systems Engineering and Evaluation Directorate, Office of the Secretary of Defense (OSD), initiated the Common Test and Training Range Architecture (CTTRA) Workshop project. The development of a common test and training range architecture requires a series of workshops designed to apply the expertise of the test and training ranges and the installed systems test facilities (ISTF) communities to the challenges of architecture development and interface standardization. A common range architecture with standardized interfaces will facilitate asset sharing between the Services, increase the industry-government dual-use potential of OSD's test and training range facilities, and lower the cost of testing. Further, common range interfaces will allow the efficient integration of new instrumentation and simulations at minimum cost. To support development of the CTTRA, there have been three workshops, each expanding the accomplishments of the previous workshop. The first workshop was conducted 20-22 April 1994. The other workshops were held 12-14 October 1994 and 21-24 February 1995. The goals of the workshop process are to: • Develop a common test and training range architecture that supports the requirements of the test, training, and installed systems test facility communities • Identify areas with the potential to yield near-term interface standardization benefits. • Identify potential OSD Central Test and Evaluation Investment Program (CTEIP) projects. Thus far, the workshops have developed a top level and second level candidate CTTRA, identified areas for interface standardization, and established standing working groups responsible for continuing development of CTTRA and selected areas for interface standardization.
    • Compression Methods for Instrumentation Video

      Whiteman, Don; Glen, Greg; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 1995-11)
      Video compression is typically required to solve the bandwidth problems related to the transmission of instrumentation video. The use of color systems typically results in bandwidth requirements beyond the capabilities of current receiving and recording equipment. The HORACE specification, IRIG-210, was introduced as an attempt to provide standardization between government test ranges. The specification provides for video compression in order to alleviate the bandwidth problems associated with instrumentation video and is intended to assure compatibility, data quality, and performance of instrumentation video systems. This paper provides an overview of compression methods available for instrumentation video and summarizes the benefits of each method and the problems associated with different compression methods when utilized for instrumentation video. The affects of increased data link bit error rates are also discussed for each compression method. This paper also includes a synopsis of the current HORACE specification, a proposed Vector HORACE specification for color images and hardware being developed to meet both specifications.
    • Configuration of Flight Test Telemetry Frame Formats

      Samaan, Mouna M.; Cook, Stephen C.; University of South Australia (International Foundation for Telemetering, 1995-11)
      The production of flight test plans have received attention from many research workers due to increasing complexity of testing facilities, the complex demands proposed by customers and the large volume of data required from test flights. The paper opens with a review of research work conducted by other authors who have contributed to ameliorating the preparation of flight test plans and processing the resulting data. This is followed by a description of a specific problem area; efficiently configuring the flight test data telemetry format (defined by the relevant standards while meeting user requirements of sampling rate and PCM word length). Following a description of a current semi-automated system, the authors propose an enhanced approach and demonstrate its efficiency through two case studies.

      Xianming, Zhao; Tingxian, Zhou; Honglin, Zhao; Qun, Lu (International Foundation for Telemetering, 1995-11)
      This paper discusses an error-correcting scheme applied to a telemetry system over HF radio channel. According to the statistical properties of transmission error on HF radio channel, the scheme uses one important diffuse convolutional code, which is threshold decoded and corrects the random or burst errors. The operation of this code is explained, and a new method for word synchronization and bit synchronization is proposed. Coding and decoding, word synchronization, and bit synchronization are all activated by software program so as to greatly improve the flexibleness and applicability of the data transmission system. Test results of error-correcting are given for a variety of bit-error-rate (BER)s on HF radio channel.
    • Data Acquisition and Distribution System (DADS)

      Shipley, Lawrence E.; Roth, Mari L. (International Foundation for Telemetering, 1995-11)
      The Data Acquisition and Distribution System (DADS) transparently collects data from a ship's combat system and transfers that data by satellite to a shore site. The system was developed by the Naval Surface Warfare Center Port Hueneme Division (NSWC PHD). DADS supports surface ship data collection, display, distribution, and debrief capabilities. NSWC PHD personnel used equipment assets developed in-house and purchased data communications hardware and software to develop DADS. A satellite terminal was placed outside Building 1380, and analog telephone lines were installed, linking the Data Communications and Control Laboratory (DCCL) with the Satellite Earth Station in Santa Paula, CA. A shipboard DADS transparently taps a ship's Combat System and collects selected data files. The data is compressed and archived. After shore site personnel select the data required for analysis, DADS encrypts it, and transmits the data via satellite to the shore site for reconstruction and analysis. DADS is unattended. The portable shipboard system equipment and software is controlled from a shore site via the International Maritime Satellite (INMARSAT). The DCC supports transmission speeds of up to 9.6 kilobits/second when connected to a communication system with this capability.

      Olyniec, Lee; Edwards Air Force Base (International Foundation for Telemetering, 1995-11)
      This paper describes the design and characteristics of a digital voice encoding circuit that uses the continuously variable slope delta (CVSD) modulation/demodulation method. With digital voice encoding, the audio signal can be placed into the pulse code modulation (PCM) data stream. Some methods of digitizing voice can require a large amount of bandwidth. Using the CVSD method, an acceptable quality of audio signal is obtained with a minimum of bandwidth. Presently, there is a CVSD microchip commercially available; however, this paper will describe the design of a circuit based on individual components that apply the CVSD method. With the advances in data acquisition technology, increased bit rates, and introduction of a corresponding MIL-STD, CVSD modulated voice will become more utilized in the flight test programs and a good knowledge of CVSD will become increasingly important. This paper will present CVSD theory, supported by graphical investigations of a working circuit under different conditions. Finally, several subjects for further study into CVSD will be addressed.