• Generating Spread-Spectrum Sequences by a Class of Chaotic Maps

      Chengquan, Au; Tingxian, Zhou; Yuxiang, Yang; Harbin Institute of Technology (International Foundation for Telemetering, 2001-10)
      Based on the fact that two topological conjugacy chaotic maps have identical dynamical behaviors, this paper proposes a method generating spreadspectrum sequences by creating chaotic maps topological conjugacy to Kent- Map, and analyses the correlation properties of the chaotic spread-spectrum sequences. The results of simulation verified the correctness of the theoretical analysis.

      Woicik, Richard; L-3 Communications Telemetry & Instrumentation (International Foundation for Telemetering, 2001-10)
      Many high-performance, reconfigurable data functions can now be integrated into a single PCI circuit board, making possible low-cost and complex systems using PCs or UNIX workstations. FPGA and PCI technologies are an excellent match to telemetry applications where commercial off-the-shelf solutions are desired, but customization is common and performance critical. A Multifunction Telemetry I/O (MFT) module was designed to exploit these technologies for both flight test and space telemetry ground systems. The reconfigurability of the module has facilitated evolutionary hardware enhancements as well as custom applications. These enhancements have been used both as building blocks for system integrators and for commercial-off-the-shelf (COTS) graphic setup, processing, archiving, and display software. The MFT module includes a standard set of telemetry functions: up to two bit synchronizers, an IRIG time decoder, and two independent telemetry serial input and output channels. The MFT module is also available on a 6U VME board. This paper describes some of the proven capabilities and applications of this module.

      Zareba, Grzegorz; University of Arizona (International Foundation for Telemetering, 2001-10)
      This article presents a measurement system based on the RS-485 interface. The presented system is an alternative solution for distributed measurement systems, which cannot be built using IEEE-488 interface due to distance limitation between elements of the system. The RS-485 interface is a base for communication between measurement instruments and uses a Master-Slave protocol to exchange data between them. One dedicated master device, usually a PC, controls all slave devices connected to the interface. To control measurement devices SCPI language is used. This solution simplifies communication between measurement devices and allows utilizing the HP-VEE environment to control any SCPI devices connected to the RS-485 network.

      Hill, Terrance J.; Nova Engineering, Inc. (International Foundation for Telemetering, 2001-10)
      Shaped Offset QPSK (SOQPSK) has been shown to be nearly identical in performance to Feher-patented FQPSK, which is the Advanced Range Telemetry (ATRM) program's Tier I waveform. Multi-h CPM has been selected as the ARTM Tier II waveform, because it offers 50% better spectral efficiency than the Tier I waveform. Both the Tier I and Tier II waveforms must operate in a multipath channel in order to meet the range community's telemetry requirements. This paper presents an analytical and experimental characterization of SOQPSK and Multi-h CPM in the presence of multipath. Quantitative results are presented which demonstrate the relative robustness of the ARTM Tier I and Tier II waveforms, in channels representative of a typical range environment.

      Brower, Alfred N.; DSPCon, Inc. (International Foundation for Telemetering, 2001-10)
      Historically, those interested in recording one or more channels with analog content of greater than or equal to 2 MHz, must use an analog recorder. In the last few years, advancements in analog-to-digital converter technology, performance enhancement in Digital Signal Processors (DSPs), and digital recording devices have made cost-effective, wideband recording applications possible through the use of all-digital techniques. This paper has three objectives: 1. It attempts to explain the benefits of a wideband digital recorder over the traditional analog variety. 2. It discusses the key elements of a wideband digital recorder. 3. It presents a realizable 10-channel, 30 Mbit PCM digital recorder solution. 4. It presents a realizable 14-channel, 2 MHz (bandwidth) digital recorder solution.

      Powell, Dave; Scofield, Don; NAVAL AIR WARFARE CENTER WEAPONS DIVISION (International Foundation for Telemetering, 2001-10)
      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 has made significant progress in the development of Global Positioning System (GPS) based Time-Space- Position Information (TSPI) tracking hardware, flight termination equipment and end-game vector scoring technology in low cost, modular packages that will allow world-wide test and training. The JAMI program is in full-scale development of advanced GPS technologies to reduce the cold start Time- To-First-Fix (TTFF) to less than 3 seconds. This paper discusses the progress of the program during the past year and the efforts planned for fiscal year 2001. Testing results of GPS receivers to levels of over 50 Gs and problems encountered in programming GPS simulator for missile flight profiles are discussed.

      Cerna, Peter J.; Klein, Pamela R.; Mullett, Joy; National Aeronautics and Space Administration; United Space Alliance; Hernandez Engineering, Inc. (International Foundation for Telemetering, 2001-10)
      The technicalities of sharing telemetry bandwidth have been addressed in design and specification for the builders of the International Space Station. But success in sharing bandwidth comes from building relationships, documenting guidelines, negotiating, understanding human nature, peer review and willingness to participate in an evolving process. The station, 240 miles above Earth, moves through space at 17,000 mph, has its mass added to by humans and machines, regularly docks with visiting spacecraft, has year-round residents, and communicates with space agencies around the globe. Each new module -- with associated computers, multiplexers, and communications buses -- creates additional telemetry demands.

      Annamraju, Venu; Kosbar, Kurt; University of Missouri – Rolla (International Foundation for Telemetering, 2001-10)
      This project investigates the feasibility of position detection in an office or industrial setting. The objective is to design a low-cost positioning system that uses the unlicensed 5.7 GHz ISM band, with centimeter accuracy and limited range. During the conceptual design phase of the system, indoor channel models will be investigated to determine which of a variety of architectures will be useful. For triangulating the position, an array of widely spaced stationary receivers and a mobile transmitter is proposed.

      Meyer, Steven; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2001-10)
      Measuring the roll rate or roll position of a rolling airframe can be difficult. Some of the smaller missiles, which have roll rates in excess of 20 revolutions per second, have the least amount of room for a roll sensor such as a laser ring gyro or a quartz rate sensor. The large roll rates coupled with the rate sensor’s resolution can cause large errors in just a few seconds. The cost for these devices can be very high. The roll problem on rolling airframes has been solved by using two magnetic sensors that are 90 degrees out of phase from each other to measure the roll. The cost of the sensor is approximately $15 and is packaged in a 20-pin-surface-mount device. This paper addresses the design and the data processing algorithm to produce roll position. The sensor and algorithm were checked for accuracy on a CARCO table.

      Baek, Won-Seok; Lee, Daniel C.; University of Southern California (International Foundation for Telemetering, 2001-10)
      We study the reliable (acknowledged) operation (i.e., ARQ scheme) of CFDP (CCSDS File Delivery Protocol) over single-hop space link. We focus on the immediate NAK mode, as specified in [1], under the assumption that PDU error events of forward and backward channels are statistically independent. We point out the problem of duplicated retransmissions due to the long propagation delay and analyze throughput efficiency. We also present modeling and analysis of the average time taken for the delivery of a file with an arbitrary size, which are more rigorous than currently available heuristics.

      Abouzahra, Mohamed D.; Patton, Bill; Tarnstrom, Guy; Wells, Dana; Massachusetts Institute of Technology; Raytheon Range Systems Engineering (International Foundation for Telemetering, 2001-10)
      Telemetry support has been a component of the instrumentation test support structure at Kwajalein Missile Range (KMR) for nearly 40 years. From a limited initial suite of manually pointed telemetry antennas, the Range has grown to include nine tracking antennas and four fixed receiving antennas. This paper describes the current modernization program at KMR that will include nine new telemetry trackers and five fixed antennas that will be networked and controlled via fiber optic links from a newly established telemetry control center on the island of Kwajalein. These upgrades will reduce operational cost and institute efficiencies, while continuing to meet Range Users’ growing requirements.

      Smith, Strether; DSPCon, Inc. (International Foundation for Telemetering, 2001-10)
      The objective of any data acquisition system is to make accurate measurements of physical phenomena. Many of the phenomena to be characterized contain data that is in the audio-frequency range between 0 and 50,000 Hertz. Examples include structural vibration, wind-tunnel measurements, turbine engines and acoustics in air and water. These tests often require a large number of channels and may be very expensive. In some cases, there may be only one opportunity to acquire the data. This paper describes a testing/measurement philosophy and the use of advances in available hardware/software systems to implement the requirements. Primary emphasis is on robustness (assurance that critical data is properly recorded), measurement/characterization of unexpected results (generated by accidents or unexpected behavior), and test safety (for both the test article and the facility). Finally, a data acquisition system that encompasses the features discussed is described.
    • Radio Frequency Test Lab Built on Non-Developmental Items

      Laird, Daniel T. (International Foundation for Telemetering, 2001-10)
      The DoD has recently mandated new acquisition, or procurement strategies for the research and development community. The policy includes using Non-Developmental Items (NDI) whenever feasible, as well as avoiding the use of proprietary sources. Such practices lesson time from specification to operation, ease of extensibility and progressive maintainability. In this paper we discuss the NDI and in-house designed test assets developed and implemented for testing the pods. Our time from specification to test was less then one year.
    • Expectation-Maximization and Successive Interference Cancellation Algorithms For Separable Signals

      Iltis, Ronald A.; Kim, Sunwoo; University of California (International Foundation for Telemetering, 2001-10)
      The expectation-maximization (EM) algorithm is well established as a computationally efficient method for separable signal parameter estimation. Here, a new geometric derivation and interpretation of the EM algorithm is given that facilitates the understanding of its convergence properties. Geometric considerations then lead to an alternative separable signal parameter estimator based on successive cancellation. The new Generalized Successive Interference Cancellation (GSIC) algorithm may offer better performance than EM in the presence of large signal power disparities. Finally, application of the GSIC algorithm to CDMA-based radiolocation is discussed, and simulation results are presented.
    • Advanced Range Telemetry (ARTM) Systems Integration at the Air Force Flight Test Center

      Briggs, James R.; Air Force Flight Test Center (International Foundation for Telemetering, 2001-10)
      The aeronautical telemetry frequency spectrum is continually shrinking. More and more government frequencies are being sold to telecommunications companies. To make matters worse, more complicated weapons systems are spurring the demand for higher data rates. The telemetry infrastructure is struggling to meet these demands as the equipment continues to age and is, in some cases, no longer supported by the manufacturer. The loss of portions of the aeronautical frequency spectrum has had significant effects at Edwards. Increasing scheduling conflicts and mission cancellations are rapidly becoming a fact of life. This paper describes the scope of the Advanced Range Telemetry Integration and Support (ARTM I&S) program as it begins to integrate ARTM-developed products into the existing telemetry infrastructure at the Air Force Flight Test Center (AFFTC). This paper will discuss the infrastructure upgrades required in order to continue supporting test and evaluation missions. Numerous challenges will be addressed including the shrinking aeronautical frequency spectrum, aging telemetry infrastructure, and the demand for higher data rates. Possible solutions will be discussed to address the growing spectrum encroachment issue.
    • Progress in Global Air Traffic Management (GATM) Avionics System Test at the Air Force Flight Test Center

      Switzer, Earl R.; Fleishans, Amy D.; Edwards Air Force Base (International Foundation for Telemetering, 2001-10)
      This paper presents a progress report on Global Air Traffic Management (GATM) avionic system test activities at the Air Force Flight Test Center. In many parts of the world today the continuing growth of commercial air traffic is running up against limits brought on by overuse of aviation resources. Air corridors in Europe and on transoceanic air routes are operating at maximum capacity. Civil Aviation Authorities (CAAs) are working these challenges on two levels—near-term incremental improvements and long-term visionary changes. Each country has a CAA; ours being the Federal Aviation Administration (FAA). Near-term solutions focus on better utilization of resources such as air space and frequency spectrum and improved performance of air traffic control facilities. Long-term visionary changes, such as free flight, could fundamentally change the current civil aviation business process model. CAA policies and standards are driving near-term improvements and migration toward long-term objectives. This initiative is referred as Communication Navigation Surveillance/Air Traffic Management (CNS/ATM). Implementation of the U.S. military’s vision, Global Reach/Global Power, requires the ability to rapidly deploy armed forces to major regional conflicts anywhere in the world, and to sustain these forces for as long as it takes to resolve these conflicts. To achieve this goal and accomplish rapid deployments while at the same time minimizing costs, the Air Force has adopted a solution that makes extensive use of CNS/ATM. The Air Force calls its initiative Global Air Traffic Management (GATM). Air Force aircraft equipped with GATM avionics will be able to use CNS/ATM capabilities such as reduced vertical separation minimum (RVSM), 8.33 kHz data links, automatic dependent surveillance - broadcast (ADS-B), and global communication networks. These capabilities make possible improved flight safety, lower fuel costs, and quicker turn times. The Air Force Flight Test Center supports the GATM initiative by providing Air Traffic Control (ATC) Communications Test Facilities and Avionic System Test (ACTFAST) capabilities to support aircraft modification programs.

      Crawford, Kevin; Johnson, Martin; NASA (International Foundation for Telemetering, 2001-10)
      NASA/Marshall Space Flight Center (MSFC) is continually looking for methods to reduce cost and schedule while keeping the quality of work high. MSFC is NASA’s lead center for space transportation and microgravity research. When supporting NASA’s programs several decisions concerning the avionics system must be made. Usually many trade studies must be conducted to determine the best ways to meet the customer’s requirements. When deciding the flight data system, one of the first trade studies normally conducted is the determination of the data bus architecture. The schedule, cost, reliability, and environments are some of the factors that are reviewed in the determination of the data bus architecture. Based on the studies, the data bus architecture could result in a proprietary data bus or a commercial data bus. The cost factor usually removes the proprietary data bus from consideration. The commercial data bus architecture’s range from Versa Module Euro card (VME) to Compact PCI to STD 32 to PC 104. If cost, schedule and size are prime factors, VME is usually not considered. If the prime factors are cost, schedule, and size then Compact PCI, STD 32 and PC 104 are the choices for the data bus architecture. MSFC’s center director has funded a study from his discretionary fund to determine an optimal low cost commercial data bus architecture. The goal of the study is to functionally and environmentally test Compact PCI, STD 32 and PC 104 data bus architectures. This paper will summarize the results of the data bus architecture study.

      Baek, Won-Seok; Lee, Daniel C.; University of Southern California (International Foundation for Telemetering, 2001-10)
      In CCSDS File Delivery Protocol (CFDP), four acknowledged modes essentially have an identical protocol for initializing and closing a file delivery. In this protocol, the system occasionally run into a state in which Sender has closed the transaction and Receiver has not closed the transaction. In this paper, we point out the danger of such state being prolonged. Such a state can be prolonged due to link occultation, extremely long propagation delay, or implementation caused by common misinterpretation of the protocol specification. We provide two failure scenarios, which occur in such a state. Then, we discuss ways of preventing such failures.

      Law, Eugene; NAWCWD (International Foundation for Telemetering, 2001-10)
      This paper will present measured data in an adjacent channel interference (ACI) environment for both filtered continuous phase frequency shift keying (CPFSK) and Feher’s patented quadrature phase shift keying (FQPSK-B) [1]. The quantity measured was bit error probability (BEP) versus signal energy per bit to noise power spectral density ratio (E(b)/N(o)). The interferers were either CPFSK or FQPSK-B signals. The results presented in this paper will be for bit rates of 5 Mb/s, one interferer 20 dB larger than desired signal, various channel spacings, and two different telemetry receivers. The ACI test effort will collect data sets at several bit rates and with one and two interferers. The results will be useful to system designers and range operators as they attempt to maximize the number of Mb/s that can be simultaneously transmitted in the telemetry bands.
    • Common-Event Network Test-Instrumentation System (CENTS) Program Status Review

      Berard, Alfredo; Boolos, Tim; Klein, Lorin D.; TW/TSI; TRW (International Foundation for Telemetering, 2001-10)
      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. This project uses advanced internetworking technology to collect data unobtrusively from multiple Line Replaceable Units (LRU's) within an aircraft without the expense of running new wiring. The data is transported to a master network controller using the existing aircraft powerlines at a raw data rate of over 10 Mbits/s. Sensors are integrated into the shells of the LRU's data bus connectors to minimize the number of aircraft modifications required for a test. CENTS began in January 2000 as an OSD CTEIP Sponsored Test Technology Development and Demonstration (TTD&D) project and is currently in Phase 2 of the effort. Phase 1 saw the successful demonstration of the use of MIL-STD-704 power busses to establish a virtual network for data transport. This paper reviews the current status and past achievements of the CENTS TTD&D program as well as describing some immediate potential pay- offs for the Test and Evaluation community in the near-term.