Coonce, Kenneth G.; Schumacher, Gary A.; Loral Data Systems (International Foundation for Telemetering, 1990-11)
      This paper describes the overall system design and performance characteristics of a complete telemetry system for a new flight test center which Loral Data Systems is currently under contract to provide to a European government. The system encompasses subsystems for airborne data acquisition and flight line check-out, a mobile ground telemetry system, and a fixed facility. The fixed facility includes a ground telemetry system for real time data processing and test control, and a data processing system for postflight analysis. The system represents a fully integrated approach to flight test systems which addresses the end-to-end requirements from airborne data acquisition and real time flight monitoring through aircraft performance and stability/control analysis. The architecture of the ground systems illustrates how preprocessing can be utilized to create powerful real time telemetry systems even with modest general purpose computer capability.

      Robillard, Jean-Claude; Brimbal, Michel; Gould Inc., Array Recorders Division; Gould Inc., Recording Systems Division (International Foundation for Telemetering, 1990-11)
      In the past 2 to 3 years, linear array recorders based on direct thermal printing technology have proven to be the recorders of choice for a large number of telemetry display stations. This technology initially developed for facsimile communications has evolved to meet speed and reliability required by the operation of recorders in the telemetry station environment. This paper discusses the performance of various direct thermal printing techniques employed. The focus is given to parameters that are critical to telemetry station operation such as quality of the chart output, maintenance and support, reliability and cost. The reliability issue is discussed at length as it is impacted by printhead thermal stress and mechanical wear. Other printing technologies available for chart recording are briefly reviewed as they may appear to be suitable alternatives in some telemetry applications.
    • Digital Signal Processing Techniques Used to Demodulate Multiple Types of Telemetry Data

      Ziegler, Frank A.; Microdyne Corporation (International Foundation for Telemetering, 1990-11)
      Telemetry systems today are required to receive a variety of modulation formats. Typically, to change the format required changing the demodulator unit or large switching systems. Using some common digital building blocks and multiplexers, the user can change demodulation mode by pressing a button. This paper describes a system that demodulates PM, FM, BPSK, QPSK and DSB AM.

      Cipolla, Frank; Seck, Gerry; Datron Systems Inc. (International Foundation for Telemetering, 1990-11)
      Datron Systems has designed a dual band EHF autotrack feed. The feed allows simultaneous reception and autotracking at K band while transmitting at Q band. The feed design and operation is discussed.

      Walsh, Edmond; S.T. Research Corporation (International Foundation for Telemetering, 1990-11)
      Small telemetry antennas (under ten feet) are popular on many ranges due to ease of handling and low cost. Unfortunately spillover, taper loss, diffraction loss, aperture blockage and feed efficiency can combine to reduce overall antenna efficiencies under ten percent. Even for a low cost antenna system, these are unacceptable losses. This paper characterizes these losses and introduces an efficient feed with a scanning acquisition beam specifically for small reflectors.

      Chavez, Tomas; Sutherland, Susan C.; White Sands Missile Range; Loral Data Systems (EMR) (International Foundation for Telemetering, 1990-11)
      The recently delivered Telemetry Data Handling System (TDHS) was designed to support the current and future needs of a multi-purpose realtime range system at White Sands Missile Range. The system provides for data acquisition, processing, and archival of PCM, PAM, and FM data. The addition of support for MIL-STD 1553 data input as presented in the SRAM II data format is currently in process by Loral Data Systems. The SRAM II format includes MIL-STD 1553 messages embedded in a traditional PCM mutiplex. These embedded 1553 messages must be extracted and processed in addition to standard processing of the PCM data. This paper discusses a general purpose solution to the handling of embedded 1553 data including: " Configuring the system components " Extracting the embedded messages " Processing the MIL-STD 1553 data " Testing the system

      James, Calvin L.; Bendix Field Engineering Corporation (International Foundation for Telemetering, 1990-11)
      Although prefiltering prevents the aliasing phenomenon with discrete signal processing, degradation in bit error performance results even when the prefilter implementation is ideal. Degradation occurs when decisions are based on statistics derived from correlated samples, processed by a sample mean estimator. i.e., a discrete linear filter. However, an orthonormal transformation can be employed to eliminate prefiltered sample statistical dependencies, thus permitting the sample mean estimator to provide near optimum performance. This paper will present mathematical justification for elements which adversely affect the bit synchronizer’s decision process and suggest an orthonormal transform alternative. The suggested transform can be implemented in most digital bit synchronizer designs with the addition of a Read Only Memory (ROM).
    • Enhancing the Capabilities of Digital Bit Synchronizers

      Windingland, Kim; Loral Instrumentation (International Foundation for Telemetering, 1990-11)
      Bit synchronizers have traditionally provided very little feedback to the user. This paper describes features that give the user a window into the quality of the signal and verification that the bit synchronizer is performing properly. In addition, this paper describes a feature that automates some of the bit synchronizer’s functions to maximize its performance. The features described are: (1) a Built-in Oscilloscope (BIO) to provide the user with a visual representation of the input signal; (2) a Link Quality Analyzer (LQA) to provide the user with a quantitative measure of the input signal’s quality (signal-to-noise ratio (SNR) measurement); (3) a Built-in Test (BIT) to provide confidence in the unit’s functional and bit error performance; and (4) an Automatic Adaptive Control (AAC) to maximize acquisition and bit error rate performance.
    • The Error-Correcting Codes of The m-Sequence

      Tingxian, Zhou; LIKUN, HOU; BINGXING, XU; Harbin Institute of Technology (International Foundation for Telemetering, 1990-11)
      The paper analyses the properties of m-sequence error-correcting codes when adapting the correlation detection decoding method, deduces the error-tolerant number formula of binary sequence with a good auto-correlation property being used as error-correcting codes, provides with a method to increase the efficiency of the m-sequence error-correcting codes and make its coding and decoding procedures in the form of framed figures.

      Saulsberry, Garen; New Mexico State University (International Foundation for Telemetering, 1990-11)
      Data continue to be produced in ever increasing rates and quantity. More transducers and instruments are being required, while those already installed are operated at higher rates to measure and verify the conditions within test environments. Increasing awareness of data security and of requirements for protecting those data once produced is an additional constraint on the test environment. Raw and processed data must be transported at higher rates to satisfy the requirements of today’s data acquisition and analysis systems. Any solution proposed must meet several tests to be considered as meeting the data transfer requirements for a data link system.

      Nimrod, Daniel W.; U. S. Army Aviation Technical Test Center (International Foundation for Telemetering, 1990-11)
      This paper briefly reviews past techniques for measuring FM deviation and discusses the limitations of past technology. Graphs of the Bessel functions are presented in terms of decibels (dB), offering a better method of measurement when used with a modern spectrum analyzer.
    • Frame Synchronization At 300 Mbps And Beyond ...

      Wunderlich, Kristin; Chesney, Jim; Bennett, Toby; Goddard Space Flight Center; Ford Aerospace Corporation (International Foundation for Telemetering, 1990-11)
      While most current ground based space telemetry acquisition systems are designed for and support data rates up to a few megabits per second (Mbps), NASA’s Tracking and Data Relay Satellite System (TDRSS) can support downlink rates up to 300 Mbps. In addition, the Advanced TDRSS (ATDRSS) is expected to support rates up to 650 Mbps. These high data rates will be required to support NASA’s future large scale operational programs such as the Space Station Freedom and the Earth Observation System. At the Goddard Space Flight Center, a prototype Frame Synchronizer card is under development which will operate at a minimum of 300 Mbps while providing a full suite of programmable functions such as 32 bit correlation, search-check-lock strategy, bit slip tolerance, fly wheeling, etc. In addition, cumulative quality data generation, on-board self diagnostics, and status/control processing are all integrated in this single card design. This level of functionality and very high data rate is made possible by the design of NASA application specific Gallium Arsenide (GaAs) Very Large Scale Integrated (VLSI) circuits to support space telemetry data system standards specified by the Consultative Committee for Space Data Systems. This paper will describe functions performed by this card and its supporting VLSI components.

      Wechel, Robert Van; Interstate Electronics Corporation (International Foundation for Telemetering, 1990-11)
      The GPS equipment developed in the tri-service GPS range applications program is now available for use. One promising application on test and training ranges is for pointing control of theodolites, laser trackers, and threat emitters. Theodolites and laser trackers are capable of extremely high accuracy in range applications, but suffer from a very narrow acquisition range, thus requiring external acquisition aiding. Unmanned threat emitters are also used that require external pointing information. In this application of GPS, a GPS receiver or translator is used on the test or training vehicle, and the position of the vehicle is downlinked to the tracking site. A pointing angle is then computed at the tracking site and is used to point or steer the theodolite, laser tracker, or threat emitter. Because of the high accuracy, of differential GPS, this method is very precise. Also, with a direct high-rate datalink, time delays for the pointing information can be very low, again providing very accurate pointing for high-dynamic vehicles. This method promises to be a highly cost-effective approach for steering these devices because it eliminates the requirement for continuous manning of the sites.

      Hoefener, Carl E.; Wechel, Robert Van; Interstate Electronics Corporation (International Foundation for Telemetering, 1990-11)
      For more than 20 years combat pilot training instrumentation has taken place on Air Force and Navy TACTS/ACMI ranges. The original ranges were designed to instrument a cylinder in space 30 miles in diameter from 5,000 feet to 55,000 feet and to handle up to eight participants. As fighter combat techniques have advanced and battle tactics have been revised to take into account more advanced weapons systems, the capabilities of the existing ranges have become extremely taxed. For example, modifications have been added on to the original systems so that the tracking altitude could be lowered to 100 feet (by adding radar altimeters to the instrumentation pods); the number of participants could be increased to 36 (by lowering the system sample rates), and the range area could be expanded (by increasing the number of ground tracking sites required from seven to a dozen or more). Clearly these were bandaid fixes, and the total capability of the ranges suffered, but since no satisfactory alternate systems were available, these systems continue to be used. During the past twenty years, however, significant advances have taken place in all areas of instrumentation system technology. By the application of modern technology, a new generation of air combat training ranges cm be made available that will greatly enhance the training capability of our armed forces and will be capable of training them in the new tactics required by the fighter weapons systems of the future. Among these training advantages will be the following capabilities: ! Tracking over an entire 25,000-square-mile or larger range area. ! Precision tracking of up to 100 participants. ! Tracking of all vehicles from ground level to 100,000-foot altitude. ! Only a few nonsurveyed portable groundsites will be required. ! An unlimited number of portable unmanned threat emitters can be provided at a fraction of the cost of existing threats. ! The entire range can be made portable. ! Modern display capability will greatly enhance pilot recall ability required for mission debriefing. By applying GPS, optimizing the datalinks, and restructuring the range design concept, these advantages can be realized. This paper discusses the application of modern range system technology to the design of the TACTS/ACMI ranges of the future.

      Roberts, Iris P.; Hancock, Thomas P.; TASC; RAJPO (International Foundation for Telemetering, 1990-11)
      TASC is currently developing for the GPS Range Applications Joint Program Office (RAJPO) the mission planner which will be used by test ranges procuring RAJPOdeveloped GPS test range instrumentation. Test Range User Mission Planner (TRUMP) is a user-friendly, PC-resident tool which aids in deploying and utilizing GPS-based test range assets. In addition to providing satellite/jammer visibility (for a Digital Terrain Elevation Data (DTED) range map) and dilution-of-precision (DOP) information, TRUMP features: C Time history plots of time-space-position information (TSPI) C Performance based on a dynamic GPS/inertial system simulation C Time history plots of TSPI data link connectivity C DTED maps with user-defined cultural features C Two-dimensional coverage plots of ground-based test range assets. This paper will discuss TRUMP’s role on the test ranges and its current features. In addition, the functionality to be added during the next development phase will be presented.
    • GPS Translator Record and Interface System (TRIS)

      Danaher, James; Structured Systems & Software, Inc. (3S) (International Foundation for Telemetering, 1990-11)
      Global Positioning System (GPS) translator signals have been used to track U.S Navy Trident missile test launches for the past 15 years. Absolute position accuracies of better than 20 meters in real-time and 8 meters in post mission have been consistently demonstrated. Flight qualified GPS translators 40 cubic inches in size have been developed for the U.S. Army Exoatmospheric Re-entry Vehicle Interceptor Subsystem (ERIS) program and are currently available for use by U.S. and allied government test ranges. More widespread use of GPS translators is constrained, however, by the great expense and size of the custom ground equipment currently used to acquire GPS translator signals and compute the position and velocity of the vehicle. To address this problem, the U.S. Air Force Western Space and Missile Center (WSMC) placed 3S under contract to design a lower-cost GPS translator processor based mainly on using commercial telemetry equipment. This paper describes how a working prototype was constructed to demonstrate the feasibility of the Translator Record and Interface System (TRIS). This prototype shows that TRIS can be built from a combination of commercially-available telemetry equipment, GPS equipment developed for the U.S. Air Force Range Applications Joint Program Office (RAJPO), and a few elements of custom equipment.

      Chi, Danny T.; Kodak Berkeley Research (International Foundation for Telemetering, 1990-11)
      Interleaving is a simple and effective way to improve the performance of an error correction scheme on a bursty channel. The interleaving of codewords will spread the effects of a long burst error into short bursts over several encoded sequences instead of a single codeword, and thus the chosen error correction scheme can correct them. This paper addresses a recently developed method, called helical interleaving ([1]) and presents some of its applications. The advantages of helical interleavers as compared with traditional interleavers are discussed. A relationship between helical interleavers and convolutional interleavers is also presented.

      Scoughton, Troy E.; Danford, Robert; New Mexico State University; Acroamatics (International Foundation for Telemetering, 1990-11)
      The system covered in this paper is the Telemetry Processing System (TPS) designed and installed for processing data acquired from high speed test sleds at Holloman AFB, NM. Because this facility operates as a test range, testing sleds from many different agencies for a variety of different purposes, prior knowledge is not always available concerning the instrumentation on the test sled to be used and therefore the type of data retrieval and processing required. The TPS must then be capable of acquiring and processing multiple data types including PAM and PDM, multiple FM streams (72 channels) and high speed PCM (4 channels) . Additionally, the requirement has been imposed for 3.2 Msample/sec analog-to-digital conversion capability for high resolution measurement of certain analog data (10 channels). When the above data are multiplexed with three time sources, eight channels of sled positional information and operated at maximum rate, the raw data exceed 15 Mbytes/sec. Depending on the scheme used to tag the samples, time stamp the data, and convert the data to engineering units, the processed data rate could have exceeded 100 Mbytes/sec and therefore the reasonable limit of existing telemetry processing technology. The TPS requires not only the capability to acquire and record this very high rate data, but also the realtime display of selected measurements. Further, the acquired data must be readily available immediately after the test for quick look evaluation, and for data selection for archival storage. This paper will explore the design process that allows the system to meet these requirements using mostly off-the-shelf or only slightly modified equipment by making clever compromises and effective use of stream separation. The paper will explore the hardware and software considerations which were examined and the solutions implemented in the final design. Development and integration of this system are currently underway, with delivery scheduled for later this year.

      Rice, William A.; Montano, William G.; White Sands Missile Range (International Foundation for Telemetering, 1990-11)
      This paper discusses the specific applications at White Sands Missile Range to certify the airborne telemetry packages, to receive, relay, and record Pulse Code Modulation (PCM) telemetry data. One of the most critical areas of data transmission throughout the Range is that of telemetry data. As digital data transmission becomes more commonplace, it becomes necessary to develop new methods for receiving, relaying, and recording digital telemetry data. A recent requirement to support reception, relay, record, and processing of a ten-megabit PCM telemetry signal drove the development of the system described in this paper. New receiving equipment was procured in order to handle the high bandwidth. Two new methods are now being used at White Sands Missile Range to relay high rate PCM data. - One is the Lightwave Fiber System. There are four telemetry lightwave links presently being used at WSMR: a multiple fiber link from the Master Relay Control Station (Jig-56) to the Telemetry Data Center (TDC), a duplex link between Jig-56 and Launch Complex 37, a simplex link from Chin Site to Jig-56 and a simplex link at Holloman Air Development Center. - The second method is the Digital Microwave Links from a TransportableTelemetry Acquisition and Relay System (TTARS) to Jig-67 and from Jig-67 to Jig-56.

      Liang, Yanxi; Dai, Lihong; Xian, Electro-Mechanical Information Technology Institute In China (International Foundation for Telemetering, 1990-11)
      With the speedy development of microelectronics and computer technology, there has arisen a particular memory telemetry branch in projectile telemetry area. Researches and experiments have been done a lot by telemetry communities in many countries. Various memory telemetry devices have been evolved for mutifarious application objects or purposes. The measurement of terminal environmental parameters is characterized by its ephemeral duration in which on-board system will undergo two, firing and impact, overloads, the latter, often reaching beyond 80,000g, is more severe than the former. Moreover, targets usually consist of such different materils as gravels, steel, or concrete, etc. In addition, the irregularity of these materits makes the mechanical conditions of the projectile penetrating into them a great deal more intricate. In order to measure the acceleration, the axial and tangential forces, the mechanism actions and the like of the parts of a fuze on impact, a high-g memory telemeter and accelerometer with an integrated operational amplifier have been developed. Field tests have also been carried out.