• QAM Multi-path Characterization Due to Ocean Scattering

      Swanson, Richard; Dimsdle, Jeff; Petersen, Tom; Pasquale, Regina; Bracht, Roger; Honeywell Federal Manufacturing & Technologies; Los Alamos National Laboratory (International Foundation for Telemetering, 2002-10)
      A series of RF channel flight characterization tests were recently run to benchmark multi-path performance of high-speed quadrature amplitude modulation (QAM) over the ocean surface. The modulation format was differential-phase/absolute-amplitude two level polar 16 QAM. The bit rate was 100 Megabits per second with a symbol period of 40nS. An aircraft radiated the test signal at 5 different altitudes. It made two inward flights, on two different days, at each altitude with vertical and horizontal polarization, respectively. Receivers, using circular antenna polarization, were in two different locations. Analysis of the resulting data shows flat fading and frequency selective fading effects.
    • RECORDERS IN NETWORKED DATA ACQUISITION SYSTEMS

      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.
    • SIGNAL PROCESSING ABOUT A DISTRIBUTED DATA ACQUISITION SYSTEM

      Kolb, John; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      Because modern data acquisition systems use digital backplanes, it is logical for more and more data processing to be done in each Data Acquisition Unit (DAU) or even in each module. The processing related to an analog acquisition module typically takes the form of digital signal conditioning for range adjust, linearization and filtering. Some of the advantages of this are discussed in this paper. The next stage is powerful processing boards within DAUs for data reduction and third-party algorithm development. Once data is being written to and from powerful processing modules an obvious next step is networking and decom-less access to data. This paper discusses some of the issues related to these types of processing.
    • SOFTWARE RADIO TECHNOLOGY AND CHALLENGES

      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.
    • SPACE COMMUNICATION DEMONSTRATION USING INTERNET TECHNOLOGY

      Israel, Dave; Parise, Ron; Hogie, Keith; Criscuolo, Ed; National Aeronautics and Space Administration; Computer Sciences Corp (International Foundation for Telemetering, 2002-10)
      This paper presents work being done at NASA/GSFC by the Operating Missions as Nodes on the Internet (OMNI) project to demonstrate the application of Internet communication technologies to space communication. The goal is to provide global addressability and standard network protocols and applications for future space missions. It describes the communication architecture and operations concepts that will be deployed and tested on a Space Shuttle flight in July 2002. This is a NASA Hitchhiker mission called Communication and Navigation Demonstration On Shuttle (CANDOS). The mission will be using a small programmable transceiver mounted in the Shuttle bay that can communicate through NASA’s ground tracking stations as well as NASA’s space relay satellite system. The transceiver includes a processor running the Linux operating system and a standard synchronous serial interface that supports the High-level Data Link Control (HDLC) framing protocol. One of the main goals will be to test the operation of the Mobile IP protocol (RFC 2002) for automatic routing of data as the Shuttle passes from one contact to another. Other protocols to be utilized onboard CANDOS include secure login (SSH), UDP-based reliable file transfer (MDP), and blind commanding using UDP. The paper describes how each of these standard protocols available in the Linux operating system can be used to support communication with a space vehicle. It will discuss how each protocol is suited to support the range of special communication needs of space missions.
    • SPACE-TIME CODING FOR WIRELESS COMMUNICATIONS

      Jensen, Michael A.; Rice, Michael D.; Brigham Young University (International Foundation for Telemetering, 2002-10)
      Signal fading and intersymbol interference created by multipath propagation have traditionally limited the throughput on wireless communications systems. However, recent research has demonstrated that by using multiple antennas on both transmit and receive ends of the link, the multipath channel can actually be exploited to achieve increased communication throughput over single-antenna systems. This paper provides an introductory description of such multi-antenna communications systems, focusing on basic explanations of how they achieve capacity gains. Computed and measured capacity results are used to demonstrate the potential of these systems.
    • SPECIFYING A PCMCIA IRIG-106 (Ch. 4) DECOMMUTATOR

      Mc Girr, Niall; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      There are many applications where an ultra-compact PC (palm-top) is required for quick analysis of PCM data. There are many design issues associated with the design of a PC-Card (PCMCIA) decommutator. • Is it possible to connect a 20Mbps PCM stream? • What outputs are required from such a card? • How many cards can be used? • Which mode to use (memory or I/O) • How to program such a card • How to develop third-party software for analysis of data This paper discusses some of these issues and the applications for such a card.
    • SPECTRAL EFFICIENCY OF 8-ARY PSK MODULATION UTILIZING SQUARE ROOT RAISED COSINE FILTERING

      Scheidt, Kelly J.; CMC Electronics Cincinnati (International Foundation for Telemetering, 2002-10)
      As frequency allocation restrictions are tightening, and data rates are increasing, it is becoming necessary to incorporate higher order modulation techniques to make more efficient use of available spectrum. When used with Square Root Raised Cosine filtering, 8-ary Phase Shift Keyed modulation is a spectrally efficient technique that makes better use of today’s RF spectrum in comparison to standard formats. This paper will discuss 8-ary PSK modulation and its spectral efficiency with a SRRC filter, along with comparisons to BPSK, QPSK, and FSK.
    • SPECTRAL EFFICIENCY/BIT ERROR RATE OF FQPSK AND OTHER NON-COHERENT SYSTEMS SUPERIOR TO COHERENT SYSTEMS FOR SMS AND BURSTED TDMA AND CDMA SYSTEMS

      McCorduck, James A.; Feher, Kamilo; MatrixSat, Inc.; University of California; Digcom, Inc. (International Foundation for Telemetering, 2002-10)
      For faster acquisition in bursted environments for SMS (Short Messaging Service) and other lower-bit rate applications, non-coherent detection techniques are proposed. Non-Coherent detection demodulators are proposed because faster acquisition capability in bursted environments can result in a reduced amount of preamble bits in the messaging frame, i.e. less overhead, resulting in an effective increase in spectral efficiency. Reducing the preamble can also provide performance enhancement opportunities for Feher Quadrature Phase Shift Keying (FQPSK) [1] and for other systems. The preamble can also be varied to provide for better Bit Error Rate (BER) performance. The lower bit rate environment also gives the opportunity to employ simpler architectures in lieu of preamble modification. Several non-coherent detection alternatives are described.
    • A STANDARD LINK-LAYER PROTOCOL FOR SPACE MISSION COMMUNICATIONS

      Parise, Ron; Hogie, Keith; Criscuolo, Ed; Schnurr, Rick; Wesdock, John; Burns, Mark; Computer Sciences Corp; NASA; ITT Industries (International Foundation for Telemetering, 2002-10)
      A necessary step for using Internet Protocols in space is to establish the basic link-layer framing protocol for delivering Internet datagrams over satellite RF links. This paper discusses the low-level data link issues related to using the ISO standard High-level Data Link Control (HDLC) protocol to support spacecraft communications. A major driver for using HDLC is its very wide usage in the Internet today and the large amount of commercially available network equipment and test equipment. The results of a high-fidelity link simulation using HDLC are presented along with results of tests performed in 2000-2001 using Internet protocols over HDLC on the UoSAT-12 spacecraft. A rationale is provided for the selection of HDLC/Frame-Relay framing along with the IETF multi-protocol encapsulation. It also discusses the historical usage of HDLC on over 70 satellite missions. The paper also describes how HDLC relates to various applications of forward-error-correction (FEC) coding techniques, such as convolutional coding and Reed-Solomon. It describes approaches for using these techniques in ways that are independent of the protocols used at the data link layer and above. It covers issues primarily related to layer 2 (Data Link) and its relationship to layer 1 (Physical). It does not cover layer 3 (Network) and above.
    • A STATUS REPORT OF THE JOINT ADVANCED MISSILE INSTRUMENTATION PROJECT HIGH DYNAMIC GPS- WE FINALLY GOT IT

      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.
    • THE STUDY OF EMBEDDED INTELLIGENT VEHICLE NAVIGATION SYSTEM*

      Shengxi, Ding; Bo, Zhang; Jingchang, Tan; Dayi, Zeng; Beijing University of Aeronautics and Astronautics; Chongqing Bashan Instrumental Factory (International Foundation for Telemetering, 2002-10)
      The intelligent vehicle navigation system is the multifunctional and complex integrate system that involved in auto positioning technology, geography information system and digital map database, computer technology, multimedia and wireless communication technology. In this paper, the autonomous navigation system based on the embedded hardware and embedded software platform is proposed. The system has advantages of low cost, low power consumption, multifunction and high stability and reliability.
    • THE SYSTEM DESIGN OF DIGITAL TWELVE-CHANNEL GPS SIMULATOR

      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.
    • TELEMETRY GROUND STATION OPEN SOURCE DEVELOPMENT

      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.
    • TIME, SPACE, POSITION INFORMATION UNIT MESSAGE STRUCTURE OVERVIEW

      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.
    • Time-Tagging Issues Relating to Networked Data Acquisition Systems

      Owens, Tara; Berard, Alfredo; Boolos, Tim; Eglin Air Force Base (International Foundation for Telemetering, 2002-10)
      The CENTS Program is a Central Test and Evaluation Investment Program (CTEIP) effort conducted by the 46th Test Wing at Eglin Air Force Base, Florida. The project uses advanced internetworking technology to collect data unobtrusively from multiple sensors located throughout the aircraft without the time and expense of installing new wires. The sensors are used to unobtrusively extract data from several Line Replaceable Units (LRU’s). The harvested data is then transported to a master network controller using the existing aircraft power lines. A critical aspect of networked data acquisition is time-tagging the data so that the data timeline can be reconstructed to a specified resolution at the conclusion of the tests. This paper will discuss the time-tagging issues that arise when developing a networked data acquisition system, especially how they relate to the current effort to develop a power line based data acquisition network. In addition this paper will detail the scheme currently being tested to time tag data in the Common Event Network Test-Instrumentation System (CENTS) developed by the 46 TW/TSI Flight Test Division, Air Armament Center, Eglin AFB, FL.
    • TRANSMIT DIVERSITY SCHEME FOR DUAL-ANTENNA AERONAUTICAL TELEMETRY SYSTEMS

      Crummett, Ronald C.; Jensen, Michael A.; Rice, Michael D.; Brigham Young University (International Foundation for Telemetering, 2002-10)
      The use of two antennas on an aeronautical telemetry transmitter is a common practice for overcoming signal obstruction that can occur during air vehicle maneuvering. However, this practice also leads to interference nulls that can cause dramatic degradation in the average signal integrity. This paper discusses the application of a transmit diversity scheme capable of overcoming this interference problem. The development leads to symbol error probability expressions that can be applied to assess the performance of the scheme relative to that of traditional schemes. Representative computational examples demonstrate the potential of the method.
    • USING BRIDGES, ROUTERS AND GATEWAYS IN DATA ACQUISITION NETWORKS

      De Selms, Tom; Veridian Engineering (International Foundation for Telemetering, 2002-10)
      Using acquisition networks requires an understanding of the capabilities, design constraints and limitations of each available network device. The proper use of bridges, routers and gateways become extremely important in large networks where dissimilar busses, protocols or applications may be found. As data acquisition networks become a reality, the instrumentation network engineer must understand the benefits of each of these network devices and when to use them.
    • USING MDP FOR TELEMETRY DATA TRANSFERS

      Chakraborti, Anirban; New Mexico State University (International Foundation for Telemetering, 2002-10)
      The current challenge has been to develop and adapt commercial Internet protocols for usage in space communications. Commercialized solutions, rather than Customized ones are cheaper, have low turnaround time and offer higher flexibility in deployment and operation. The focus of the study was to modify and develop UDP/IP based protocols commonly used in commercial Internet for reliable data transfers in space environment. Multicast Dissemination Protocol was designed by Naval Research Laboratory to provide reliable multicast data and file transfer delivery on the top of general UDP/IP platform. It is very suited for bulk data transfer over the Internet. We have extended its usage in space channels and evaluated it as a solution to meet key challenges in space communications like high bit error rates and asymmetric channels. We have also tried to optimize the performance of the protocol in the terms of throughput, reliability, integrity and security of data. The evaluation test were carried on our Space to Ground Link Simulator which uses PPP to model point to point satellite links and correspond to low capacity systems as found in small satellite systems.
    • THE VEHICLE MONITORING SYSTEM BASED ON GPRS

      Xu, Liu; Qishan, Zhang; Beijing University of Aeronautics and Astronautics (International Foundation for Telemetering, 2002-10)
      The Vehicle Monitoring System based on GPRS is a system using GPRS network to transmit data, including location data, time data and so on .It has many advantages compared with those systems based on other communication modes. The key of the system lies in how to build up the connection with exterior data network. In this paper, the constitution of the system is introduced, and the course of building up connection with exterior data network is described in detail.