SMITH, DARREN C.; CHINA LAKE NAVAL WEAPONS CENTER (International Foundation for Telemetering, 1990-11)
      The Naval Weapons Center (NWC) A-6E flight test program, like so many DOD efforts, is caught in the vise of declining budgets and increasing demands and requirements. The A-6E data management system has evolved over 30 years by extensive testing and reflects all the “real world” experience obtained over that period of time. This paper will address that data management system, specifically how data is recorded on the A-6E during flight test and some associated issues as well as how that data is managed for analysis use, all within the environment of tight budgets and increased requirements.
    • Accuracies of Bomb-Scoring Systems Based on Digitized 2- and 3-D TV Images

      Rieger, James L.; Naval Weapons Center, China Lake, California (International Foundation for Telemetering, 1990-11)
      Three-dimensional images produced by film or analog television have been used for bomb scoring by triangulation for many years. Use of solid-state imaging devices and digitization of analog camera outputs can improve the accuracy of such measurements, or make accuracy lower or (worst of all) of random accuracy if interpreted incorrectly. This paper examines some of the issues involved, and tabulates the maximum accuracies available for a given system.
    • An Advanced Commanding and Telemetry System

      Hill, Maxwell G. G. (International Foundation for Telemetering, 1990-11)
      The Loral Instrumentation System 500 configured as an Advanced Commanding and Telemetry System (ACTS) supports the acquisition of multiple telemetry downlink streams, and simultaneously supports multiple uplink command streams for today’s satellite vehicles. By using industry and federal standards, the system is able to support, without relying on a host computer, a true distributed dataflow architecture that is complemented by state-of-the-art RISC-based workstations and file servers.

      Rhea, Donald C.; Scardello, Michael A.; Moore, Archie L.; SPARTA, Inc.; Perimeter Computer Systems, Inc. (International Foundation for Telemetering, 1990-11)
      Rapid technology growth in the aerospace industry continues to manifest in increasingly complex weapons systems and system driven weapons systems platforms which must be supported in the flight test environment. This growth in complexity often surpasses the capabilities of many ground based real-time and post-flight processing and display systems, leaving these systems perpetually behind the power curve when compared to data/information processing, presentation and distribution requirements set forth by today’s flight test engineering community. Many flight test programs are accepting less than optimal results from these systems, therefore, the amount of information presently obtained (per flight hour) limits the results acquired during a test program, creating a more costly test and evaluation budget. As an integral participant in the development and testing of high technology aircraft and weapons systems, the U.S. Air Force Flight Test Center’s (AFFTC) Advanced Data Acquisition and Processing Systems (ADAPS) development is bridging the gap between requirements and capability by distributing current system architectures to provide incremental performance upgrades in specific areas of need in lieu of entire system replacements. This paper will discuss the current real-time processing, distribution and display capability that exists at the AFFTC and the planned phased upgrade of this tightly coupled system to a more flexible and extensible distributed architecture that will be increasingly responsive to the dynamic nature of test and evaluation of modern weapons systems and weapons systems platforms.

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1990-11)
      Development of a next generation modular PCM system to satisfy a variety of applications for a decade or more resulted in a greater design effort than the use of the latest device technology to satisfy a current customer’s functional needs. Functionality of the existing product line, as well as competitive products, was coupled with a survey of users’ present and future needs, and their opinions of both the good and bad features of existing products. The survey covered system architecture, system throughput, signal conditioning, packaging, software, telemetry, recording and support. A phased development schedule implemented current customer requirements first, followed by development of ultimate system capabilities. Proof-of-concept prototyping proved extremely cost effective as significant changes and improvements in both mechanical and electrical designs resulted from the prototyping. Extensive internal design reviews permitted a wide range of engineering talent to contribute to the overall design. This major undertaking was started just over two years ago with mechanical prototyping and environmental testing of the new “Loaf-of-Bread” (LOB) packaging concept. The core system functionality, composed of 17 different types of functional modules, is now entering the production phase following full environmental qualification. Expanded system functionality is currently developed through proof-of-concept operational hardware which will be upgraded to production hardware within the year. The mechanical modularity achieved by the LOB package will permit system users to make low cost, periodic upgrades of key system functional elements by slice replacement without obsolescence of the majority of the users’ delivered hardware.

      Koontz, Rollin H.; Hatfield, Daryl C.; Pacific Missile Test Center (International Foundation for Telemetering, 1990-11)
      This paper reports on the design of a B-band flight termination antenna (FTA) for use on the Advanced Medium Range Air to Air Missile (AMRAAM). The antenna is a low profile structure composed of an etched circuit board measuring 1.6 by 10.0 by 0.010 inches mounted inside a 0.17 inch deep cavity formed in the back of the AMRAAM harness cover. There is a metallic cover over the cavity which connects to the metalized harness cover constituting a ground plane for the antenna. The antenna is easily tuned through use of two metallic slugs in close proximity to the ends of the antenna elements. The active circuit of the antenna is composed of a 3-element folded dipole photoetched from copper clad Duroid. The center element is driven through a microstrip matching transformer which is printed on the opposite side of the antenna elements. A quarter wave open circuited stub is also printed opposite the elements to provide a virtual short such that no physical contacts are necessary between the transformer and the driven element. The matching transformer connects to the 50 ohm source at the center of the antenna through a side projecting microstrip tab which in turn is connected to a semi-rigid coaxial line. The antenna exhibits improved bandwidth and excellent pattern coverage, particularly in the critical roll plane. All of the antenna parameters will be presented and discussed.

      Stegall, Ralph L.; Stephens, Bobby C.; Government Electronic Systems Division (International Foundation for Telemetering, 1990-11)
      The AN/MPS-39 Multiple Object Tracking Radar (MOTR) is a new precision instrumentation system designed to support range safety, weapon development, operational test and evaluation, and training exercises involving multiple participants. A coherent MTI (moving target indicator) variant, the subject of this paper, has been developed for MOTR using discretionary IR&D funds. A zero recurring cost “softwareonly” version of this MTI variant has been successfully tested. The architecture for a low-cost hardware adjunct designed to increase MTI detection range and simultaneously provide clutter-suppressed operator displays has also been developed. In this paper, a brief description of MOTR is given and its adaptability to three-pulse MTI is presented, along with expected performance results. The implementation of the MTI software only version is described in some detail and the results of tests are shown. The hardware adjunct is briefly described. Possible applications of this variant are cited and future directions MOTR coherent real-time processing can take are given.
    • Antenna Modification for In-Flight Projectile Fuze Data

      Sandberg, Craig D.; US. ARMY ARMAMENT RESEARCH, DEVELOPMENT AND ENGINEERING CENTER (International Foundation for Telemetering, 1990-11)
      Microstrip antenna designs have gained importance due to the requirements and restrictions of projectile size and desired data. Most projectile testing programs require in-flight data during the entire trajectory. Original microstrip antenna designs created extensive variations in the antenna radiation pattern as the projectile was rotated about its axis. These variations led to distortion and total loss of data during critical events of a projectile fuze test. Developments and data that have led to modified designs in order to reduce these nulls will be discussed in the following sections.

      Greenwood, Dan; NETROLOGIC, Inc. (International Foundation for Telemetering, 1990-11)
      The FAA Sponsored a six months research program to investigate the application of neural networks to controlling aircraft. It was found that properly configured neural networks offer powerful new computationally robust methods to generate command vectors corresponding to collision free routes. Methods using neural networks which capture the expertise employed by controllers in resolving conflicts were formed. This paper shows that many of the neural network techniques applied to ATC can also be applied to drone control. Two different networks are presented: a multi-layer feed-forward network using back-propagation and a method using a potential field where a gradient measure is employed to maintain the aircraft separation in real time.

      CHIMENE, MARK C.; ROCKWELL INTERNATIONAL MISSILE SYSTEMS DIV. (International Foundation for Telemetering, 1990-11)
      Telemetry system requirements are driven by technological developments in other areas, thus the capabilities of one are mirrored in the capabilities of the other. Contemporary systems typically involve two or more digital subsystems, each operating at a unique clock rate; an increase in complexity that needs to be addressed by the Telemetry system designer. Although the subsystems may be exchanging information, complete synchronization is seldom realized in discrete systems. Because the Telemetry system must provide information sufficient to isolate data/process corruption, it must accept data from the various subsytems at different rates and times. What is needed is a technique to de-couple the Telemetry system clock rate from that of the Subject system or any of its subsystems. This technique must bridge the gap between the synchronous data transmission fundamental to the Telemetry system and the asynchronous data transfer required by the various non integrated subsystems. This paper will discuss the design challenges offered by such a Subject system for both real time and post flight analysis. It will discuss how the restrictions imposed by the IRIG standards and anticipated mission requirements factored into developing the architecture for a Generic Multi-Port Digital Telemetry Interface.
    • A Band-Width Limiting Circuit Improves Telemetry System Operation

      Lillie, Derek S.; LORAL CONIC (International Foundation for Telemetering, 1990-11)
      Present bandwidth limiters use a six-pole bessel filter approach to limit the power bandwidth of the transmitter to IRIG-106-86 requirements. However, the filter must be reconfigured if frequency changes in the data stream are desired for system requirement purposes, eg. adding encryption. The circuits set forth herein will provide for frequency change of the data stream while also providing a power increase by reducing the out of band power.
    • Chinese Development on Aero-space Telemetry Ground Station

      Chang-jie, Shi; The Ministry of Aero-space Industry P.R.C. (International Foundation for Telemetering, 1990-11)
      This paper introduces the systematic design features of development of Chinese aero-space telemetry ground station from the following seven respects: 1. The fundamental factors to promote the 1980s’ development of telemetry ground station. 2. Increasing the flexibility of telemetry ground station. 3. The approach of one-time system design and multisteps development. 4. Decreasing the effect and influence of host computer. 5. Increasing the efficiency of buses. 6. To pay attention to magnetic recorder. 7. According to realistic utility to determine the configuration and specification of telemetry ground station.
    • Color Extension for the HORACE TV Compression Protocol

      Gattis, Sherri L.; Rieger, James L.; Naval Weapons Center, China Lake, California (International Foundation for Telemetering, 1990-11)
      The HORACE protocol[5] was designed as a common medium of exchange for digitized black-and-white television images at varying resolutions at bit rates from below 9600 to over 50M bits per second. At the 1 time of the protocol’s creation, “hooks” were added to allow use of the system to transmit and receive two-and three-color images from an NTSC, RGBY, RGB, or “S-type” input and produce outputs in the same format, but those systems remained undefined. Two systems implementing various features of the extended color protocol have been built and demonstrated by two different manufacturers, and an effort to standardize the protocol for all users and manufacturers is underway.

      Deutermann, Alan; Schaphorst, Richard; Delta Information Systems, Inc. (International Foundation for Telemetering, 1990-11)
      As the role of television in the aerospace industry has expanded so has the need for video telemetry. In most cases it is important that the video signal be encrypted due to the sensitive nature of the data. Since this means that the signal must be transmitted in digital form, video compression technology must be employed to minimize the transmitted bit rate while maintaining the picture quality at an acceptable level. The basic compression technique which has been employed recently, with successful results, is a combination of Differential PCM and Variable Length coding (DPCM/VLC). This technique has been proposed to the Range Commanders Council to become a possible standard. The purpose of this paper is to compare the basic DPCM/VLC technique with alternative coding technologies. Alternative compression techniques which will be reviewed include Transform coding, Vector Quantization, and Bit Plane coding. All candidate techniques will be viewed as containing four elements -- signal conditioning, signal processing, quantization, and variable length coding. All four techniques will be evaluated and compared from the stand point of compression ratio and picture quality.

      Law, Eugene L.; Pacific Missile Test Center (International Foundation for Telemetering, 1990-11)
      This paper will describe the Pacific Missile Test Center’s (PMTC) approach to a computer controlled telemetry receive and record system. The advantages of this system include: fast, accurate equipment setup and interconnection, automatic verification of operational status, and simplified signal monitoring. PMTC personnel developed the system architecture and software. The system hardware is all unmodified off-the-shelf equipment. The main design drivers were cost, reliability, and minimizing the effect of any single point failure. The system uses many individual switches instead of a small number of large switch matrices. Manual patching capability has been maintained. This patching system provides a backup solution if all the computers get “zapped”. The patching system also provides increased signal routing flexibility.

      Hart, Michael James; White Sands Missile Range (International Foundation for Telemetering, 1990-11)
      The seven WSMR Transportable Telemetry Acquisition Systems (TTAS), have served WSMR well as primary telemetry tracking systems since their acquisition over twenty years ago. Increasing maintenance demands for the original analog position control system (the antenna feed, servo power amplifiers, and position compensation) coupled with the potential for substantial tracking system performance improvement and self-diagnostic capability offered by current technology led to the establishment of a new instrumentation development task at WSMR whose objective was the development of a new, almost totally digital prototype tracking system to replace the aging analog control system in one of the TTAS’s. A modern conical scan feed has replaced the original monopulse feed, pulse-width-modulated power amplifiers have replaced the originals using SCR’s, and a VMEbus-based computer using a real-time operating system has replaced the analog compensation and overall control of the system. In this paper, following an overview of the prototype tracking system, the results of the development of a new position control algorithm for the prototype tracking system are described using root loci, computer simulation, and from the actual tracking system using servo test software developed for the computer controller. The results of the study of the old analog control system using computer simulation are presented for comparison. Problems encountered with the TTAS directly affecting position control are also presented. The new position control algorithm was designed to accommodate all of the critical tracking system nonlinearities (power amplifier saturation, current limiting, dead band, and control output saturation), all tracking modes (autotrack, manual, and using external pointing data), different operating bandwidths, and all possible drive inputs to the system. It has converted the tracking system from a type-1 to a type-2 control system improving the dynamic capability of the TTAs.

      Law, Eugene L.; Pacific Missile Test Center (International Foundation for Telemetering, 1990-11)
      This paper will present the results of a study to correlate tape dropouts and data quality. A tape dropout is defined in the Telemetry Standards as “a reproduced signal of abnormally 1 low amplitude caused by tape imperfections severe enough to produce a data error” Bit errors were chosen as the measure of data quality. Signals were recorded on several tracks of a wideband analog instrumentation magnetic tape recorder. The tape tracks were 50 mils wide. The signal characteristics were analyzed when bit errors or low reproduce amplitudes were detected.

      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.