• HIGH DATA RATE RADAR AND TELEMETRY SIGNAL COLLECTION

      Cumming, Colin J.; Frontier Engineering, Inc. (International Foundation for Telemetering, 1984-10)
      Collection of radar and telemetry data has always been limited by bandwidth and storage capacity factors. This paper examines some of the constraining factors in achieving very high data rates and storage capacities. A number of new technologies are examined for applicability. A special purpose modular architecture oriented towards high speed bulk data acquisition is presented. Several systems are described including systems based on Winchester disks, high speed parallel transfer disks, bulk RAMs, HDDR, and others. Special emphasis is placed on the unique data acquisition requirements of radar and telemetry signal collection.
    • A METHOD FOR OBTAINING REAL TIME RECOVERY VEHICLE DATA

      Diebel, Dean L.; Recovery Systems Instrumentation Branch (International Foundation for Telemetering, 1984-10)
      In the development and design of parachutes, select data parameters are required for evaluation. These parameters give the designer dynamic information in actual environments providing stress, load, and glide ratio information. At present this information (altitude, rate of descent, total velocity, acceleration, dynamic pressure and attitude), is obtained by the use of space positioning methods. Meterological data, used to calculate some of these parameters, are obtained from rawinsonde balloons which are launched one half to two hours before and after the drop test. Typical combined data accuracies are on the order of plus or minus f ive percent with most of these errors being ascribed to the fact that the weather data is not taken at the time of the test and atmospheric conditions change rather quickly during the morning hours when the tests are typically done. A method has been developed which will measure meterological data real time. Direct measurements are taken via transducers ie. pressure, acceleration, attitude, temperature and humidity. These transducers are combined in the microprocessor circuitry to obtain final data prior to solid state recording or transmission. This paper will describe the methods and justifications for pursuing a different type of data gathering system.
    • COMMAND, CONTROL AND COMMUNICATIONS (C³) FOR THE DEFENSE METEOROLOGICAL SATELLITE PROGRAM

      Williams, Stephen L., Captain; Kinney, Thomas W.; USAF Space Division; Harris Government Information Systems Division (International Foundation for Telemetering, 1984-10)
      This paper describes the architectural philosophy and the interaction between the DMSP C³ ground system and the strategic and tactical users of DMSP imagery data. Some of the ongoing activities relating to future enhancements and survivability are also explored. At the present time, the ground systems Satellite Operations Center (SOC) has been installed at Offutt Air Force Base, Nebraska, and is supported by the two remote Command Readout Stations (CRS’s) at Fairchild Air Force Base, Washington, and Loring Air Force Base, Maine. All commanding, planning and telemetry processing is centralized at the SOC. Backup and redundant subsystems and communications services are provided for reliable operation plus there is an internet with the Air Force Satellite Control Facility (AFSCF) for early orbit and anomaly support.
    • THE STEERABLE LUNEBURG LENS AS A COMMUNICATION LINK ANTENNA

      Higgs, James A.; Worth, Richard A.; Teledyne Micronetics (International Foundation for Telemetering, 1984-10)
      A review of the Luneburg Lens and its use as an antenna aperture is presented. Also discussed are methods of electromechanical and electronically switchable operation along with design criteria. Applications in the field of data link communications and telemetry are suggested and the performance of several operational systems are outlined.
    • AN OVERVIEW OF THE GPS DEMONSTRATION PROGRAM FOR RANGE APPLICATIONS

      Knoernschild, Gene F.; Rockwell International (International Foundation for Telemetering, 1984-10)
      This paper describes a program to evaluate the use of an integrated GPS/INS system as the source of Time/Space/Position for participant tracking in range applications.
    • SPIN RATE AND POSITION MEASUREMENT TELEMETRY SYSTEM

      Richter, I.; Hochman, D. (International Foundation for Telemetering, 1984-10)
      As part of an effort to reduce a projectile’s spin, a telemetry system was developed in order to measure spin rate and position of a given point on a round during flight. The telemetry system consisted of twelve special sensors (sensitive to sun light) which were installed on the shell’s perimeter and an electronic system, that converted the sensors’ analog output into a conventional PCM stream that was transmitted, received, and decoded into position and spin rate. The telemetry system although exposed to very severe environmental conditions such as high G’s, vibration and temperature, operated successfully.
    • ASSESSMENT OF METROLOGICAL PARAMETERS BY MEANS OF FIBER-OPTIC SENSORS

      Kist, Rainer; Fraunhofer-Institut für Physikalische Messtechnik (International Foundation for Telemetering, 1984-10)
      Fiber-optic sensors will get their share of the sensor market only if they can be made available at low prices or if they can solve metrological problems that have no suitable solutions within conventional sensor techniques. Since fiber-optic components are in general still high cost items, fiber-optic sensors are not likely to become competitive in this respect within the near future. These sensors do provide, however, important specific advantages such as isolation against high voltage, immunity against electromagnetic fields as well as explosive and/or corrosive environments, possibility of miniaturized and compact packaging of the sensing element, and application within a broad temperature range. Multimode fiber-optic sensors for parameters such as temperature, pressure, level , and refractive index are on the market already or very close to being commercialized. Monomode fiber-optic sensors are not yet on the market due to their more demanding technology and the corresponding higher cost level . They are expected, however to provide at acceptable costs in a forseeable future high precision solutions for metrological tasks under specific conditions (e.g. Sagnac gyroscopes, hydrophones, temperature measurement in a microwave field).
    • A UNIQUE 155 MM BALLISTIC SHOCK AIR GUN

      Stewart, E. Kenneth; US Army Armament Research and Development Center (International Foundation for Telemetering, 1984-10)
      A rifled soft recovery air gun used as a ballistic simulator is described and compared to conventional smooth bore air guns. These gun systems provide shock tests for qualification, quality control, and research and development of many items, including telemetry systems and components. The laboratory environment in which they operate is responsible for lower test costs than field tests, and for a higher average number of retests of expensive telemetry units.
    • COMMAND AND TELEMETRY IN AUTONOMOUS SPACECRAFT DESIGN

      Turner, Philip R.; Jet Propulsion Laboratory, California Institute of Technology (International Foundation for Telemetering, 1984-10)
      Spacecraft autonomy is provided by placing control authority for functional operations on board the spacecraft. A three-step control process utilizes sensed information to determine and initiate appropriate control actions. A critical design feature is the selection of appropriate sensory data and the means by which it is passed to the onboard control resource. This paper summarizes some major steps in the evolution of autonomous design features for planetary exploration spacecraft.
    • A MODULAR, LARGE SCALE, INTERACTIVE TELEMETRY DATA ANALYSIS SYSTEM

      Luten, Robert H.; Computer Technology Associates, Inc. (International Foundation for Telemetering, 1984-10)
      The Test and Evaluation Data Center (TEDC) was originally developed at Lockheed Missiles and Space Company with the objective of providing a data processing facility to support major systems test evaluation. This data center was responsible for the acquisition, reduction (to engineering units), analysis, protection, and management of all (telemetered) test data produced during system integration and test activities. The TEDC was developed as a local area network, consisting of several VAX-11 computers and other commercial off-the-shelf hardware, which could acquire telemetry data at rates greater than 1 Mbps (potentially 4-5 Mbps) and, with rapid turnaround, make it available to a large number of engineering analysts via interactive graphics terminals. This paper discusses the engineering, design, and development of the TEDC, including descriptions of the major algorithms, data structures, and techniques used to optimize its overall performance. Discussion of plans for the evolutionary growth of the system are also included.
    • A ONE-WAY DATA LINK OPERATING WITH EXTREME WEAK SIGNALS

      Goebel, Walter; DFVLR - German Aerospace Research Establishment (International Foundation for Telemetering, 1984-10)
      For maritime applications of distress communications via geostationary satellites a special method of signal processing was developed, called superposition technique. The data frame containing the alert message is transmitted from a distress equipment repeatedly. After being relayed by the satellite the signal is detected and improved by superimposing the frames. Around 14 dB is the actual processing gain. Thus a distress buoy is able to transfer a message from all over the world with high reliability by only transmitting a power of 50 mW omnidirectionally over a slant range of about 40 000 km. The described system, called the Distress Radio Call System (DRCS) was tested in a Coordinated Trials Program (CTP) of 6 nations. Both in a simulation phase and in a field test under exactly the same environmental conditions the DRCS with its superposition technique was able to detect signals with lowest signal-to-noise-density ratio without error. In laboratory tests using GAUSS channel conditions, a system threshold of 13 dB-Hz could be demonstrated. In a real environment (North Cape) 15 dB-Hz was the lower limit for error-free reception. CCIR approved a recommendation in June, 1984 for a system operating through geostationary satellites at 1.6 GHz being a DRCS-type with very little modifications.
    • S-BAND CIRCULARLY POLARIZED MICROSTRIP PHASED ARRAY

      Coombs, Dennis L.; Ball Aerospace Systems Division (International Foundation for Telemetering, 1984-10)
      A highly efficient circulary polarized S-band microstrip planar phased array is described. The array is: • Electronically steerable in elevation and azimuth • Highly efficient at the subarray level (greater than 60 percent) • Well matched for active impedance with a near cos a scan performance • Designed for optimum G/T performance • Designed to have a thin profile but be extremely strong The microstrip elements, phase shifters and combiner network are described in detail and their operation is explained.
    • PROGRAMMABLE PCM ENCODER

      Poirier, Norman C.; Wheeler, Thomas P.; Department of Electrical and Computer Engineering; Northeastern University (International Foundation for Telemetering, 1984-10)
      This paper will present the concept of a general purpose pulse code modulation (PCM) encoding system which has all the major operating parameters under stored program control. This type of encoder can be used in a large variety of scientific/engineering data gathering applications by simply programming an onboard EPROM to tailor the encoder to the specific mission requirements. Key words: Pulse Code Modulation (PCM), Encoder, Data Acquisition, Parity, Programmable Filter, Multiplexer.
    • A Programmable Data Acquisition System with Integrated Test and Calibration Facilities

      Zach, Adolf; Gandert, Rüdiger; Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt e.V. (DFVLR) (International Foundation for Telemetering, 1984-10)
      In 1985 the new Advanced Technologies Testing Aircraft System (ATTAS) will be operable at DFVLR Braunschweig. For this research aircraft a flexible, highly accurate and testable data acquisition system was developed. It consists of a modular and distributed microprocessor system with signal conditioning units situated near the sensors. It is controlled by a master unit with an integrated PCM encoder. The flexible signal conditioning featuring software-controlled parameters and adaptable signal inputs, can be tested automatically via the analog calibration bus using switchable signal paths. The system will be presented in detail and its performance will be shown by typical examples of application within ATTAS.
    • PROBLEMS AND SOLUTIONS FOR NONSYNCHRONOUS TELEMETRY AND DATA SYSTEMS

      Grant, Eugene N.; Martin Marietta Orlando Aerospace (International Foundation for Telemetering, 1984-10)
      The modern pulse code modulated (PCM) telemetry or data transmission system should have its input data rates synchronized by its own, or an external clock. Either arrangement allows all pulsed input data to arrive in a known clocked time sequence. Data transmission is orderly, and all input and output gating occurs at required time intervals. Events in nature do not always follow an ordered sequence, but data transmission requires the pattern and order found in a synchronous system. Today’s missiles and aircraft do not always have the nicety of synchronous systems. In many systems today, the PCM will run at one clock rate, while the navigational computer will be set to a second rate, the autopilot processor at a third and the weapons handling system at a forth. In the slower data use systems such as “1553", data can be stored, deleted, refreshed, and data buffers or memory used. Output data loss is not too important, since output data use rates are well below input data rates. However, research and development aircraft and missile test flight applications require real time or at least time-tagged data. Transient responses cannot be lost because of clock skips or phase differences between clocks. This paper will review and explain data loss through clock skips or phase differences. The paper will show causes and effects with real time flight systems that have flown recently. Solutions such as direct synchronization, phase locked loops between separate clocked systems, and sample and hold first-in, first-out buffers, will be discussed. The applications and limitations of these solutions will be described. A development nonsynchronous system for a flight missile will be reviewed, showing block diagrams, component utilization, circuit schematics, and command application interfaces and software. The intent of this paper is not to give ultimate solutions to the clock synchronization problem, but to alert the telemetry system designer to this data problem. The paper will help define his solutions before he finds his data lost, missing or scrambled on flight test records.
    • CANADIAN FORCES PCM TELEMETRY PROCESSING AND DISPLAY SYSTEM

      Glenesk, Major L.B.; Marriott, Captain J.L.; Aerospace Engineering Test Establishment, CFB Cold Lake (International Foundation for Telemetering, 1984-10)
      Canadian Forces (CF) flight test facilities were recently updated to support testing of the CF-18 aircraft by the development of a new ground based PCM telemetry processing and display system (TPADS). Additional enhancements to this system are currently underway, or being considered, to further improve flight test mission control and data processing functions and produce a system capable of meeting CF flight test requirements into the 1990’s.
    • DESIGN OF OPTIMAL NYQUIST AND PARTIAL RESPONSE FIR DIGITAL FILTERS USING LINEAR PROGRAMMING TECHNIQUES

      Liang, Junn-Kuen; Lu, Fu-Chao; Chung Shan Institute of Science and Technology (International Foundation for Telemetering, 1984-10)
      The design of a Nyquist filter for generating a band-limited pulse for data transmission with the zero intersymbol interference is formulated as a linear programming (LP) problem and the Steiglitzs program [18] is modified and then used to design this type of pulse shaping filters. The advantage of the present approach, as compared to other methods, with regard to design speed and filter optimality, are described, and illustrated by means of examples.
    • AN OVER THE HORIZON COMMAND/DATA LINK SYSTEM

      Turner, William C.; Electro Magnetic Processes, Inc. (International Foundation for Telemetering, 1984-10)
      An Over the Horizon Command/Data Link is fraught with unforeseen design problems. Multipath, ducting, holding aircraft position and altitude, as well as base-band signal processing equipment interface anomalies contribute to link degradation beyond predicted quality. This paper describes a three channel link, L-band, MDI-band, and S-band, over which command, video, and telemetry respectively are transmitted. Successful operation is currently achieved over a 100 mile range.
    • SATELLITE ACQUISITION USING AN AUTOMATED TECHNIQUE

      Reinhard, Kenneth L.; Darlington, John C.; Ford Aerospace & Communications Corporation (International Foundation for Telemetering, 1984-10)
      Automated acquisition of a satellite’s downlink signal by the main beam of a ground station’s tracking antenna is complicated by the presence of antenna pattern sidelobes and potential large uncertainties in the spatial and/or frequency location of the signal. Sidelobe acquisition prevents autotracking and telemetry reception, and large uncertainties require time for coordinated antenna and receiver search. Use of an auxiliary antenna assists in resolving the sidelobe intercept problem, and a high speed digital receiver alleviates the problems associated with spatial and frequency uncertainty. The antenna and receiver, under processor control, constitute a fully automated system. The associated processor software controls the antenna motion during the search phase, selects the proper receiver configuration for the expected signal environment, makes the main beam versus sidelobe intercept decision and switches to autotrack mode upon successful signal acquisition.
    • TELEMETRY FOR EMC-TESTS ON ELECTRO-EXPLOSIVE DEVICES (EED’S) IN WEAPON SYSTEMS

      Freymann, Dieter; Messerschmitt-Bölkow-Blohm (MBB) Dynamics Division (International Foundation for Telemetering, 1984-10)
      A data transmission system using fibre-optics data links has been developed to determine the compatibility of weapon systems electro-explosive devices to radiated electromagnetic environments. The EED’s are instrumented with temperature sensors which are as sensitive to pulsed RF as to continuous wave RF. Significant progress has been made in reducing the RF coupling of the sensors and in decreasing size, weight and power consumption of the decentralized telemetry system. After the description of the system some examples of measurements are reported. In coordination with the Military Departments this specific data transmission system will become a Military Standard in the near future.