• International Telemetering Conference Proceedings, Volume 39 (2003)

      International Foundation for Telemetering, 2003-10
    • THE CASE FOR MIS-MATCHED FILTERING IN NONLINEARLY AMPLIFIED FQPSK AND GSM INTER-OPERABLE SYSTEMS

      Gonzalez, Maria C.; University of California, Davis (International Foundation for Telemetering, 2003-10)
      Structures for power-efficient systems, requiring the use of non-linear amplifiers and thus Mis-Matched filtering, are presented. These architectures allow for changeable amounts of power, bit rate, and modem selectable formats. The benefits include power/spectral efficiency, in addition to robust operation in mobile environments . Alternatives to matched filter receivers are addressed for power constrained systems associated with mobile systems in frequency selective channel environments. Two types of modulation format FQPSK[1][2][3] and GMSK[4], with different mismatch filters at the receiver, are analyzed.
    • Telemetry Data Encoder with an Embedded GPS Receiver

      Rivera, Alan; Herley Industries (International Foundation for Telemetering, 2003-10)
      This paper outlines the GPS data acquisition of two PCM encoders. The design of the first PCM Encoder uses an embedded GPS Receiver module, the Thales G12- HDMA receiver. The G12 Receiver has been integrated into the electronics of the PCM Encoder to provide a seamless tool for the Telemetry Engineer to acquire GPS position and time data with the sensor data acquired from the PCM Encoder. The second telemetry encoder discussed in this paper adds the GPS Interface Module for the Time Space Position Unit (TSPI) currently under development at Herley Industries. The TSPI Unit will also be integrated with the PCM Encoder tools to create a seamless user interface. The TSPI unit is available in both the “Low Dynamic (JTU-I)” and the “High Dynamic” (JTU-II).
    • SIMULATED PERFORMANCE OF SERIAL CONCATENATED LDPC CODES

      Panagos, Adam G.; University of Missouri at Rolla (International Foundation for Telemetering, 2003-10)
      With the discovery of Turbo Codes in 1993, interest in developing error control coding schemes that approach channel capacity has intensified. Some of this interest has been focused on lowdensity parity-check (LDPC) codes due to their high performance characteristics and reasonable decoding complexity. A great deal of literature has focused on performance of regular and irregular LDPC codes of various rates and on a variety of channels. This paper presents the simulated performance results of a serial concatenated LDPC coding system on an AWGN channel. Performance and complexity comparisons between this serial LDPC system and typical LDPC systems are made.
    • ALAMOUTI SPACE-TIME CODING FOR QPSK WITH DELAY DIFFERENTIAL

      Rice, Michael; Nelson, Tom; Brigham Young University (International Foundation for Telemetering, 2003-10)
      Space-time coding (STC) for QPSK where the transmitted signals are received with the same delay is well known. This paper examines the case where the transmitted signals are received with a nonnegligible delay differential when the Alamouti 2x1 STC is used. Such a differential can be caused by a large spacing of the transmit antennas. In this paper, an expression for the received signal with a delay differential is derived and a decoding algorithm for that signal is developed. In addition, the performance of this new algorithm is compared to the standard Alamouti decoding algorithm for various delay differentials.
    • EXPENDABLE LAUNCH VEHICLE VIDEO SYSTEM

      Brierley, Scott; Lothringer, Roy; Boeing Company (International Foundation for Telemetering, 2003-10)
      The Delta expendable launch vehicle has been flying onboard video cameras. The camera is an NTSC analog camera that directly modulates an FM transmitter. A standard FM deviation is used to maximize link performance while minimizing transmitted bandwidth. Pre-emphasis per CCIR recommendation 405 is used to improve the video signal-to-noise ratio. The camera and transmitter obtain power from either a separate battery or the vehicle power system. Lighting is provided by sunlight, or a light may be added when sunlight is unavailable. Multiple cameras are accommodated by either using multiple transmitters or by switching the individual cameras in flight. IRIG-B timing is used to correlate the video with other vehicle telemetry.
    • FQPSK ANALOG/DIGITAL IMPLEMENTATIONS FOR LOW TO ULTRA HIGH DATA RATES IN 1Gb/s RANGE SYSTEMS

      Chen, Dijin; McCorduck, James A.; Feher, Kamilo; University of California, Davis; MatrixSat, Inc.; DIGCOM, Inc. (International Foundation for Telemetering, 2003-10)
      For simpler implementations of ultra high bit rate systems, combined analog/digital techniques, described here in, provide implementations with the smallest number of component count utilizing minimal “real-estate” and smallest DC power. While digital implementations with tradition Read Only Memory (ROM) and Digital to Analog Converters (DAC’s) have been proven in several commercial, NASA -CCSDS recommended, and U.S. DoD-IRIG standardized Feher’s QPSK (FQPSK) [2,3] products, such implementations can be further simplified, and in particular for ultra high bit rate product applications. Several waveform generating techniques such as linear approximation, analog approximation and mixed analog and linear approximations are investigated using preliminary simulation results.
    • IMPLEMENTATION OF UNMANNED TELEMETRY GROUND SYSTEM USING MICROWAVE LINK

      Dong-soo, Seo; Sung-hoon, Jang; Sung-hee, Han; Heung-bum, Kim; Agency for Defense Development (International Foundation for Telemetering, 2003-10)
      Unmanned Telemetry Ground System (UTGS) was implemented in Defense System Test Center (DSTC), Agency for Defense Development (ADD). The components of UTGS are Antenna, NPS (Network Power Switch), RCB (Receiver/Combiner/Bit synchronizer) and microwave link. We have installed RCB which is composed of receiver, combiner and bit synchronizer. RCB can be controlled and monitored by RS232 serial communication and microwave network. NPS controls its power supplies. UTGS sends PCM stream to local site using E1-class HDSL and microwave link. This system is possible the signal acquisition and reduction of man power at remote site. The usability and performance of UTGS was proved in flight tests. This paper describes the hardware, software design and an implementation of UTGS.
    • STANDARD USER DATA SERVICES FOR SPACECRAFT APPLICATIONS

      Smith, Joseph F.; Hwang, Chailan; Fowell, Stuart; Plummer, Chris; National Aeronautics and Space Administration; SciSys; Cotectic, Ltd. (International Foundation for Telemetering, 2003-10)
      The Consultative Committee for Space Data Systems (CCSDS) is an international organization of national space agencies that is branching out to provide new standards to enhanced reuse of spacecraft equipment and software. These Spacecraft Onboard Interface (SOIF) standards will be directed towards a spacecraft architecture, as a distributed system of processors and busses. This paper will review the services that are being proposed for SOIF. These services include a Command and Data Acquisition Service, a Time Distribution Service, a Message Transfer Service, a File Transfer Service, and a CCSDS Packet Service. An Instrument & Subsystem “Plug & Play Service is currently under study, but is included in this paper for completeness.
    • AIR-GROUND TELEMETRY SYSTEMS FOR RESEARCH HELICOPTERS

      Kasper, Eugene F.; Leong, Gary; Ames Research Center (International Foundation for Telemetering, 2003-10)
      This paper describes the development of a compact mobile telemetry system using commercial-off-the-shelf components. The personal computer-based systems support microwave pulse code modulation and serial spread-spectrum radio modem telemetry. The mobile ground station provides data display and archiving of test activities, air-ground communications between experimenters and the flight test crew, and acts as a flight test Differential Global Positioning System base station. The success of the systems indicates that functional telemetry capabilities can be established for small flight test programs at modest cost.
    • THE SPREAD-SPECTRUM MULTIPLEXING TELEMETRY SYSTEM USING PARALLEL MOVE EQUIVALENT SEQUENCE

      Wang, Yongjian; Zhao, Honglin; Zhou, Tingxian; Harbin Institute of Technology (International Foundation for Telemetering, 2003-10)
      In this paper, based on the parallel move equivalent sequence of m sequence ,one type of CDM telemetry system is issued. Also the method for anti multi-path interference(MPI) of the system is proposed and its performance is analyzed. We proved that this system not only holds the merits which are inherent in common spread-spectrum communication system, but also has better transmission efficiency.
    • THE DESIGN OF INTERFACE MODULE FOR VENDOR MANAGING SYSTEM BASED ON INTERNET

      Liuxu; Qishan, Zhang; Beihang University (International Foundation for Telemetering, 2003-10)
      With the high-speed development of IT, the managing method of the vendor has been changed from the manpower management into the network management .The paper discusses the structure of vendor managing system based on Internet. And it introduces the important constitute part of the system in detail, which is called interface module, including the design scheme of hardware and software.
    • RUGGED AND RELIABLE COTS STORAGE SOLUTIONS FOR DATA ACQUISITION SYSTEMS

      Tsur, Ofer; M-Systems (International Foundation for Telemetering, 2003-10)
      Due to the rotating mechanism in mechanical disks, they cannot provide the top-level reliability required for operation in harsh military environments. This paper describes three COTS alternatives to mechanical disks: ruggedized mechanical disks, solid-state flash disks and stacked PC Cards. It discusses their cost-effectiveness and aspects such as environmental specifications, endurance and data reliability. It highlights several methods used by flash disks to enhance endurance and reliability, as well as flash pricing and density trends. It presents data security requirements in actual emergency situations, and how flash disks can meet these requirements. It concludes with a feature-by-feature comparison of ruggedized disks, flash disks and stacked PC Cards.
    • Flight Safety System for Unmanned Air Vehicle

      Pérez-Falcón, Tony; Kolar, Ray; Reliable System Services Corp.; Atlantic Coast Technologies, Inc. (International Foundation for Telemetering, 2003-10)
      A Flight Safety System (RAFS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of flying Over-the-Horizon (OTH) and outside test range airspace. In addition to the flight safety application, the described full-duplex data link is suitable as a backup command and control link for UAV’s, and for sensor control & data exfiltration. The IRIDIUM satellite system was selected to provide the communications link and because of its global coverage and requisite data throughputs. A Risk Reduction activity ensued to quantify IRIDIUM performance. Hardware and software was developed to demonstrate the feasibility of using IRIDIUM in a flight safety scenario.
    • ONLINE DISTRIBUTED VEHICLE AND MACHINERY HEALTH MANAGEMENT

      Dietz, Anthony; Friets, Eric; Finger, William; Bieszczad, Jerry; Miller, Matt; Freudinger, Lawrence; Creare Incorporated; NASA (International Foundation for Telemetering, 2003-10)
      Modern aircraft and space vehicles routinely sense and record vast quantities of information relevant to assessing the vehicles’ health. However, limitations imposed by the bandwidth of telemetry and network connections prevent real-time transmission of the complete data set to central stations for analysis. An online health-management system suitable for bandwidth-limited network environments that enables interrogation of the full data set by ground-based operators is described. The system uses distributed objects organized in a data processing hierarchy linked by a buffered data-management subsystem. Reduced health information is routinely transmitted, but dynamic reports may be requested on demand from any object.
    • SMART ANTENNA (DIVERSITY) AND NON-FEEDBACK IF EQUALIZATION TECHNIQUES FOR LEO SATELLITE COMMUNICATIONS IN A COMPLEX INTERFERENCE ENVIRONMENT

      Haghdad, Mehdi; Feher, Kamilo; University of California Davis; American SkySat; FQPSK Consortium – Digcom, Inc. (International Foundation for Telemetering, 2003-10)
      An improved performance smart diversity was invented to improve the signal performance in a combined selective fading, Additive White Gaussian Noise (AWGN), Co-channel interference (CCI) and Doppler shift environment such as the LEO satellite channel. This system is also applicable to aeronautical and telemetry channels. Smart diversity is defined here as a mechanism that selects at each moment the best branch in a n-branch diversity system based on the error quality with no default branch and no prioritization. The predominant novelty of this discovery is the introduction of multi level analog based Pseudo Error Detectors (PSED) in every branch. One of the advantages of PSED is that it is a non redundant error detection system, with no requirement for overhead and no need for additional valuable spectrum. This research was motivated by problems in LEO satellite systems due to low orbit and high relative speed with respect to the ground stations. The system is independent of the modulation techniques and is applicable to both coherent and non-coherent detections. The results from simulations using dynamic simulation techniques and hardware measurements over dynamic channels show significant improvement of both the Bit Error Rate (BER) and the Block Error Rate (BLER).
    • Generalized Successive Interference Cancellation/Matching Pursuits Algorithm for DS-CDMA Array-Based Radiolocation and Telemetry

      Iltis, Ronald A.; Kim, Sunwoo; University of California (International Foundation for Telemetering, 2003-10)
      A radiolocation problem using DS-CDMA waveforms with array-based receivers is considered. It is assumed that M snapshots of N(s) Nyquist sample long data are available, with a P element antenna array. In the handshaking radiolocation protocol assumed here, data training sequences are available for all K users. As a result, the received spatial-temporal matrix R ∈ C^(MN(s)x P) is approximated by a sum of deterministic signal matrices S(k)^b ∈ C^(MN(s) N(s)) multiplied by unconstrained array response matrices A(k) ∈ C^(N(s)x P). The unknown delays are not estimated directly. Rather, the delays are implicitly approximated as part of the symbol-length long channel, and solutions sparse in the rows of A are thus sought. The resulting ML cost function is J = ||R - ∑(k=1)^K S(k)^bA(k)||(F). The Generalized Successive Interference Cancellation (GSIC) algorithm is employed to iteratively estimate and cancel multiuser interference. Thus, at the k-th GSIC iteration, the index p(k) = arg min(l ≠ p(1),...,p(k-1)) {min(A(l)) ||R^k-S(l)^bA(l)||(F)} is computed, where R^k = ∑(l=1)^(k-1) S(pl)^bÂ(pl). Matching pursuits is embedded in the GSIC iterations to compute sparse channel/steering vector solutions Â(l). Simulations are presented for DS-CDMA signals received over channels computed using a ray-tracing propagation model.
    • SPACE-BASED TELEMETRY AND RANGE-SAFETY STUDY TRANSCEIVER AND PHASED-ARRAY ANTENNA DEVELOPMENT

      Whiteman, Don; Sakahara, Robert; Kolar, Ray; NASA; Reliable Systems Services Corporation (International Foundation for Telemetering, 2003-10)
      The transmission of high-rate telemetry data for space-based relay systems yields unique system requirements. The NASA Space-based Telemetry and Range-Safety (STARS) study evaluated system design requirements during Phase-1 flight tests. STARS Phase-2 efforts include the development of a high-rate transmitter and antenna system to demonstrate prototype system performance capabilities and new technologies for future operational systems to be incorporated into the NASA Next Generation Launch Technology (NGLT) vehicles. Phase-2 Range User (telemetry) system performance requirements and a prototype implementation approach are presented.
    • JOINT FRAMEWORK PROJECT: A FLIGHT TEST DATA PROCESSING SYSTEM

      Modi, John J.; Essman, Tony L.; Brandon, Douglas H.; Waller, Joe W.; Hester, Robert S.; Pham, Fern L.; Bui, Vien X.; Green, Dan C.; Kerzie, Mark G.; Lockheed Martin (International Foundation for Telemetering, 2003-10)
      The Joint Framework Project (JFP) is an effort to conjoin the software data processing pipeline frameworks between Lockheed Martin’s Flight Test Data Centers. The JFP integrates the existing Data Processing Framework (DPFW) with the Joint Enterprise Test System (JETS) data products concept of pipelines. The JFP is constructed with simple governing concepts of data pipes and filters, engineered to manage post flight and real time test data for LM Aeronautics Flight Test mission support, and the results are presented here. The JFP is an Object-Oriented dynamically configurable framework that supports LM Aeronautics Flight Test programs. The JFP uses the Adaptive Communications Environment (ACE) framework, an open source high-performance networking package, to implement the components. The joint framework project provides a real time and an interactive / background post flight test data processing environment reproducing MIL-STD 1553, ARINC 429, Pulse Code Modulation (PCM), Time Space Position Information (TSPI), Digital Video, and High Speed Data Bus (HSDB) data streams for flight test and discipline engineers. The architecture supports existing requirements for the flight test centers, and provides a remarkably flexible environment for integrating enhancements. The JFP is a collaborative effort consisting of LM Aero Flight Test software teams at Marietta, Fort Worth, Edwards Air Force Base, and Palmdale. A prototype will be presented of the JFP addressing the data specific treatment of demultiplexing, decommutation, filtering, data merging, engineering unit conversion, and data reporting. An overview of the distributed architecture is presented, and the potential for the JFP extensibility to support future flight test program requirements is discussed.
    • Tracking Multiple Airborne 802.11b Wireless Local Area Networks to Extend the Internet to Aircrafts in Flight

      Wei, Mei Y.; Billings, Donald; Leung, Joseph G.; Aoyagi, Michio; NASA (International Foundation for Telemetering, 2003-10)
      Wireless local area networks (WLANs) enable the extension of the Internet to aircrafts in flight. To establish this wireless network segment, commercial-of-the-shelve (COTS) 802.11b wireless Ethernet bridges were used. Wireless Ethernet bridges were chosen over optical wireless technology and Internet protocol (IP) satellite modems mainly because of their lower costs, ease and flexibility of implementation. Additionally, 802.11b wireless networks allow a wide range of mobile data devices such as laptop computers and personal digital assistance high-speed wireless access to critical information and applications resided on the aircrafts networks. Since 802.11b WLAN media is shared and traffic generated by other users will degrade the overall performance of the network. With the continual wide spread use of 802.11b WLAN, an aircraft in flight will experience network congestions and poor performance across all the frequency channels. The congestion and poor performance issues can be minimized by tracking the airborne wireless LAN using highly directional antenna and RF filtering. The method of tracking multiple 802.11 wirelesses LAN and the RF subsystem will be described. The applications of 802.11b wireless networks to man and unmanned aircrafts flight research will be discussed.