• Optimum Symbol Synchronization

      James, Calvin L.; AlliedSignal Technical Services Corporation (International Foundation for Telemetering, 1994-10)
      Although most closed-loop synchronizers employ maximum likelihood estimators for symbol value decisions, in general, their symbol timing estimates are not optimum. It would seem only natural that an optimum timing estimator would choose interval partitions based on maximizing the observed sample signal-to-noise ratio. The symbol synchronizer described below achieves optimum performance when decisions on present symbol values are based on current and previously-received symbol samples. This procedure attempts to reestablish the interval independence criterion, thereby reducing timing estimator variance. The realization presented is motivated by an open-loop maximum a posteriori (MAP) structure analysis.
    • Aircraft Distance Measurement System

      Filho, Nelson Whitaker (International Foundation for Telemetering, 1994-10)
      The Aircraft Distance Measurement System (ADMS) could be used in Flight Test application to determine the aircraft position and speed during takeoff, landing and acceleration-stop performance test within runway limits using a microwave link.
    • Space Tracking Systems/ Options Study

      Grelck, John; Ehrsam, Eldon; Means, James A. (International Foundation for Telemetering, 1994-10)
      This paper presents the findings of the Space Tracking Systems/Options Study (STS/OS) and indicates its impact on the telemetering community. The STS/OS was commissioned by Air Force Test & Evaluation (AF/TE) to develop a long range plan (vision and roadmap) for the AF Test & Evaluation (T&E) community to ensure affordable capabilities (telemetry, tracking and commanding) for the future (2003-2008). The study was conducted by the Air Force Materiel Command (AFMC), Space & Missile Systems Center (SMC), Detachment 9, at Vandenberg AFB (VAFB), with support from the primary AFMC T&E centers, the Air Force Operational Test & Evaluation Command (AFOTEC), and the Air Force Space Command (AFSPC). Both "open air" aeronautical and astronautical test needs were considered. The study solicited requirements for existing and future programs, extrapolated existing and planned test capabilities out into the future, then compared the two to identify future shortfalls in capabilities and specific actions that are necessary to insure that the future program needs can be met. Three critical types of testing were identified that cannot be satisfied with existing or planned instrumentation. These are: large area testing (LAT), over the horizon testing (OTH), and space weapons testing (SWT). A major deficiency was also uncovered in end game scoring for air and space intercepts, where inadequate capability exists to perform the required vector miss-distance measurement. This paper is important to the telemetering community because it identifies the Global Positioning System (GPS) as the primary time space position information (TSPI) system for all future open air testing. GPS provides a passive capability that permits each vehicle to determine its own precise TSPI. Means must be provided, however, for the vehicle to relay its position to the appropriate range control center. The paper shows that the problems with down linking telemetry, aircraft buss data, digital audio, digital video, and TSPI collectively represent the need for a very capable datalink. Likewise, the need to uplink commands, synthetic targets, synthetic backgrounds, and target control information also represents the need for a very capable datalink. With its extensive expertise in RF linkages, the telemetering community is ideally suited to address this need for a robust datalink for the future of T&E.
    • Deterministic Distribution of Telemetry and Other Replicated Information

      Gustin, Thomas W.; SYSTRAN Corp. (International Foundation for Telemetering, 1994-10)
      Discover how it is now possible to memory-link all man-in-the-loop and machine-in-the-loop elements, as global resources that share information at memory-access speeds, to provide a unified system paradigm that avows: "the data is there, on time, every time." Regardless of configuration, if your past, present, or future system consists of more than one computer, and it interactively mixes information sources and destinations (e.g. Telemetry data streams, I/O interfaces, information processors, etc.) to achieve a highly integrated system, then the critical path to real-time success mandates a high performance, reliable, and deterministic communications methodology. This softwareless, future technology is already successfully sharing information in other real-time markets and applications, and is ready for more challenging applications.
    • Network Configuration for Range Interconnectivity

      Douglas, Steven R.; Naval Warfare Assessment Division (International Foundation for Telemetering, 1994-10)
      A demonstration of near real-time performance assessment for the Program Executive Officer for Cruise Missiles Project and Unmanned Aerial Vehicles, Cruise Test Directorate, PEO(CU)-CT, was conducted between 22 March 1994 through 4 May 1994. The demonstration involved the temporary installation of a portable TOMAHAWK telemetry recording and telecommunications capability at the Air Force Development Test Center range at Eglin Air Force Base, Florida and a receiving telecommunications capability at the Naval Warfare Assessment Division (NWAD), Corona, California. The system was successfully used on 4 May 1994 to record TOMAHAWK missile telemetry data in real-time in support of Operational Test Launch (OTL)-163 and to transfer that data to the weapons system performance analysts at NWAD in near real-time. The one hour and three minutes of flight data was compressed in real-time as it was recorded, then, after completion of the flight, the data was transferred to NWAD in about 12 minutes using the switched 56 kbps network. Additional transfers using the Defense Commercial Telecommunications Network (DCTN) were also conducted. All transfers were secured using ethernet encryptors. The data was processed by both the NWAD telemetry ground station and the TOMAHAWK workstation complex. This paper quantifies the results and documents the lessons learned from this demonstration and proposes a standardized system design for possible implementation at TOMAHAWK test range sites in the future. A position is taken that for situations where the remote site (e.g. other range or data analysis site) does not exercise direct operational control over the test/host range, near real-time data relay solutions are not only as adequate, but in many cases are preferable to real-time solutions.
    • A Dielectric Resonator Stabilized Frequency Modulation Oscillator in the S-Band

      Banghua, Zhou; Mingsheng, Huang; Xinan Electronic Engineering Institute (International Foundation for Telemetering, 1994-10)
      With the development of the airborne telemetry technique, it will be demanded that the transmitting sets on the missiles are more reliable and smaller. A frequency modulation (FM) oscillator stabilized with a dielectric resonator (DR), which can operates in the S-band directly, is presented. The FM oscillator is of simple circuit, reliable operation in the stabilization, small size, light weight and low cost. It will have a certain prospect of application in the airborne telemetry transmitting sets.
    • The Common Airborne Instrumentation System Program Management Overview

      Brown, Thomas R., Jr.; Naval Air Warfare Center, Aircraft Division (International Foundation for Telemetering, 1994-10)
      The Department of Defense, 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. The CAIS Program Office will conduct requirements analyses, manage system upgrades, and provide full life cycle support for this system. It is initiating several requirements contracts to provide direct ordering opportunities for DoD users to easily procure defined test instrumentation hardware. The program office will provide configuration management, inventory control, maintenance support, system integration, engineering support, and software management. In addition, it will continue to enhance the current system and develop new items to meet future requirements. Where existing equipment provides added benefit, this equipment may be added to the official CAIS family.
    • The Universal Signal Conditioning Amplifier

      Medelius, Pedro J.; Hallberg, Carl; Larson, William E.; Becker, Dean; I-NET, Inc.; NASA; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      A state-of-the-art instrumentation amplifier capable of being used with most types of transducers has recently been developed at the Kennedy Space Center. This Universal Signal Conditioning Amplifier (USCA) can eliminate costly measurement setup time and troubleshooting, improve system reliability, and provide more accurate data than conventional amplifiers. The USCA can configure itself for maximum resolution and accuracy based on information read from a RAM chip attached to each transducer. Excitation voltages or currents are also automatically configured. The amplifier uses both analog and digital state-of-the-art technology with analog-to-digital conversion performed in the early stages to minimize errors introduced by offset and gain drifts in the analog components. A dynamic temperature compensation scheme has been designed to achieve and maintain 12-bit accuracy of the amplifier from 0 to 70E C. The digital signal processing section allows the implementation of digital filters up to 511th order. The amplifier can also perform real-time linearizations up to fourth order while processing data at a rate of 23,438 samples per second (23.438 kS/s). Both digital and analog outputs are available from the amplifier.
    • Sub-Optimum Receiver Filters

      Osborne, William P.; Gutierrez, Alberto; New Mexico State University (International Foundation for Telemetering, 1994-10)
      This paper presents a method for analyzing the performance of a digital receiver when using standard analog filters in place of the ideal matched filter. Expressions are developed for the probability of error and performance loss of the sub-optimum receiver as functions of the minimum eye value and noise bandwidth of the suboptimum receiver filter. A method is developed for choosing the best sub-optimum filter in the sense of minimizing the probability of error. The best sub-optimum Bessel filter of order less than or equal to 6 is specified in terms of 3-dB bandwidth and filter order for a system with a rectangular transmit pulse. This method is applicable to other transmit pulse shapes and can be applied to channels with limited bandwidth. The optimum 3-dB bandwidth obtained here can be scaled relative to the symbol rate to correspond to any practical system.
    • Wideband FM Telemetry Application

      Neuens, Jim; Veda Incorporated (International Foundation for Telemetering, 1994-10)
      A Wideband FM Telemetry System was developed by Veda Incorporated and Boeing Commercial Airplane. This system supports Boeing 777 flight testing and will support future Boeing test efforts. This is an upgrade to the system previously used by Boeing for testing other planes. The design interfaces to the new Boeing Data Acquisition and Analysis systems and provides 15 Megabits per second Telemetry at ranges up to 180 miles. This paper provides details regarding the following design and integration issues: o) RF Transmitter Design o) RF Receivers o) Airborne Antenna o) Ground Based Antenna o) Data Interfaces o) System Performance o) Problems / Solutions
    • Application of Dither to Low Resolution Quantization Systems

      Borgen, Gary S.; NAWCWPNS (International Foundation for Telemetering, 1994-10)
      A significant problem in the processing chain of a low resolution quantization system is the Analog to Digital converter quantization error. The classical model of quantization treats the error generated as a random additive process that is independent of the input and uniformly distributed. This model is valid for complex or random input signals that are large relative to a least significant bit. But the model fails catastrophically for small, simple signals applied to high resolution quantization systems, and in addition, the model fails for simple signals applied to low resolution quantization systems, i.e. one to 6 bits resolution. This paper will discuss a means of correcting this problem by the application of dither. Two methods of dither will be discussed as well as a real-life implementation of the techniques.
    • An Algorithm for Efficient Computation of the Fast Fourier Transform Over Arbitrary Frequency Intervals

      DaBell, Steve; Motorola GSTG (International Foundation for Telemetering, 1994-10)
      In many signal processing and telemetry applications only a portion of the Discrete Fourier Transform (DFT) of a data sequence is of interest. This paper develops an algorithm which enables computation of the FFT only over the frequency values of interest, reducing the computational complexity. As will be shown, the algorithm is also very modular which lends to efficient parallel processing implementation. This paper will begin by developing the frequency selective FFT algorithm, and conclude with a comparative analysis of the computational complexity of the algorithm with respect to the traditional FFT.
    • Dual Function Transponder: A Data Link for the Next Generation

      DeViso, Hans; Troth, Bill (International Foundation for Telemetering, 1994-10)
      Future U.S. Navy at-sea and littoral battle group training range instrumentation requires a new, secure, high data rate link This link must be capable of providing the ranges with the capacity to increase the number of players, increase the amount of threat simulation, and allow an improved Global Positioning System (GPS) based position tracking system to be implemented This paper describes a Dual Function Transponder (DFT) capable of operating on any R-CUBED (Relay, Reporter, Responder) based range as well as any TACTS/ACMI range without modification of either range type. In addition, the DFT provides a new increased data rate capability for use by planned future ranges, enabling a dramatic increase in the number of participants as well as significantly increasing the quantity of data that can be communicated by each player. Miniaturization and programmability are the keys to this development and many of the methods used are described.
    • Portable Airborne Digital Data System Recorder

      Harris, Kevin E.; Veda Incorporated (International Foundation for Telemetering, 1994-10)
      Veda Incorporated has developed an airborne instrumentation recorder for a major commercial aircraft manufacturer. The recorder was developed for use in the aircraft company's Portable Airborne Digital Data System (PADDS), a small scale data acquisition and monitor system used for flight testing. The recorder is designed around an off-the-shelf 8mm tape drive, the Exabyte 8505. It records asynchronous, variable-rate data in a proprietary 24-bit recording format, and allows the data to be played back in real time. Its RS-422 control interface is designed to imitate the recorder used in the company's large scale data acquisition system, the Ampex DCRSi-II. Special provisions allow it to withstand the environment of an airplane's EE bay.
    • Planned Evolution of Range Telemetry and Communications into the Public Data Network

      Erdahl, Mike; Loral Test & Information Systems (International Foundation for Telemetering, 1994-10)
      The area of range telemetry and communications has been under budget constraints and interoperability enhancement requirements for some time. The near-term onslaught of multimedia communications offerings by telephony and communications companies is certain to cause range engineering personnel to conduct extensive research and possibly make numerous decisions on procurements and technologies before standards are finalized. This paper will address a low-risk migration path for range telemetry to the new multimedia communications for ranges based on current capabilities. This migration path has an end goal of positioning the ranges to take advantage of future multimedia communications as they become available, while leveraging off of current products and procurements, without a major investment.
    • The Use of Digital Signal Processors in Front-End Weather Satellite Telemetry Processing

      Lide, David A.; Talabac, Stephen (International Foundation for Telemetering, 1994-10)
      This paper discusses the use of DSP technology in the embedded real time ingest and pre-processing of weather satellite data. Specifically, case studies are presented in the use of Texas Instrument TMS 320 processors as front-end handlers of GOES MODE AAA and GOES GVAR data formats.

      O'Cull, Douglas C.; Microdyne Corporation (International Foundation for Telemetering, 1994-10)
      With the increased concerns for reducing cost and improving reliability in today's telemetry systems, many users are employing simulation and automation to guarantee reliable telemetry systems operation. Pre-Mission simulation of the telemetry system will reduce the cost associated with a loss of mission data. In order to guarantee the integrity of the receive system, the user must be able to simulate several conditions of the transmitted signal. These include Doppler shift and dynamic fade simulation. Additionally, the simulator should be capable of transmitting industry standard PCM data streams to allow pre-mission bit error rate testing of the receive system. Furthermore, the simulator should provide sufficient output power to allow use as a boresite transmitter to check all aspects of the receive link. Finally, the simulator must be able to operate at several frequency bands and modulation modes to keep cost to a minimum.

      Jin, Minglu; Zhang, Qishan; Shenyang Institute of Aeronautical Engineering; Beijing University of Aero. & Astr. (International Foundation for Telemetering, 1994-10)
      In this paper, by using computer simulations, the interference of channel data in the SDM telemetry system is investigated, the performance of the copy demultiplexing is examined, and finally the selection rule of Walsh functions is recommended.

      Martin, Fredric W. (International Foundation for Telemetering, 1994-10)
      Use of top-down design principles and standard interface techniques provides the basis for a global telemetry data collection, analysis, and satellite control network with a high degree of survivability via use of distributed architecture. Use of Commercial Off-The-Shelf (COTS) hardware and software minimizes costs and provides for easy expansion and adaption to new satellite constellations. Adaptive techniques and low cost multiplexers provide for graceful system wide degradation and flexible data distribution.

      Horan, Stephen; Minnix, Timothy; New Mexico State University (International Foundation for Telemetering, 1994-10)
      Small satellites have been perceived as having limited access to NASA's Space Network consisting of the TDR satellites and associated ground terminals. This paper presents the potential for access of the space network using basic small satellite design constraints and a simple helical antenna for the communications links. From the analysis derived through simulation of the orbit of both satellites, small satellites can be shown to have up to 30 minutes per orbit of single-TDRS access. Data rates on the order of 100 kbps are possible in this configuration with total daily data volumes in excess of 100 Mbits being achievable. Design parameters are given for a variety of orbital inclination angles and spacecraft transmission powers to illustrate the expected available contact time for such small satellites to the Space Network. This is compared with typical access time through a fixed ground station.