• Sensing of Irregularities on Fast Moving Surfaces by Microwaves and Millimeterwaves

      Ishii, T. Koryu; Marquette University (International Foundation for Telemetering, 1988-10)
      Fine cracks and irregularities on a fast moving conducting surface were detected by the use of microwave and millimeter wave radio responder techniques. The interrogation angle was restricted to an oblique incidence angle less than ±0.5 degree from the surface. The fast moving conducting surface was surrounded by both fast moving and stationary reflective conducting structures. Experimental methods and results from a fine crack 0.1 mm wide, 0.9 mm deep, and 25 mm long on a conducting surface travelling with a speed of 20.23 m/s and measured at 10.525 GH(z) and 73 GH(z) are presented. The reflection-type microwave radio responder consisted of a 10.525 GH(z) 50 mW Gunn diode cw transmitter, a circulator, and a horn antenna used as the interrogator. The receiver in the same responder consisted of the same horn antenna, the circulator and detector diode. The detector diode output was observed with a Norland 3106R digital memory oscilloscope. A reflex kylstron VA 250 was used as the transmitter signal source for the millimeter wave responder. There was a distinct difference between the responder output patterns with uncracked and cracked surfaces. It is therefore possible to use this type of responder for hair-line crack detection of fast moving conducting surfaces. It was also found that this type of radio responder can detect the surface irregularity even before the hairline crack actually occurs.
    • Several Problems in Chinese Development of Telemetry Technology

      Chang-jie, Shi; Shang-ren, Li; Ministry of Aeronautics and Astronautics; Beijing Research Institute of Telemetry (International Foundation for Telemetering, 1988-10)
      1. What is the reason for the telemetry ground station using computer technology widely and deeply? 2. How to solve the problem of measuring fast varing signal? 3. Bit rate of telemetry ground station.
    • Simple Digital Encoder for NTSC Composite Video

      Milles, George T.; Naval Weapons Center (International Foundation for Telemetering, 1988-10)
      The need exists to encode NTSC composite video into a serial digital bit stream for encryption prior to transmission. Further, this need exists in places where power and volume are at a premium. This paper describes a simple solution using the Continuously Variable Slope Delta Modulation technique of encoding all lines and fields in real time and is usable with clock rates from 5 to 25 MHz. The circuits presented use only a 5-volt power supply and two active devices: a comparator and either a dual flip-flop or serial shift register.
    • Software Control of a High Speed, Modular Signal Conditioner and PCM Encoder System

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1988-10)
      The increasing channel capacity and complexity of flight test data acquisition systems have made the problems of physical distribution of the system throughout the test aircraft and determining the system configuration a very time consuming and costly portion of the flight test process. These problems are complicated because the new aircraft, irrespective of size, have more complex systems and less space is available to install the classical data acquisition and recording system. The solution to the installation problem is to have a highly modular system that can be configured as either a distributed system with remote multiplexing and a PCM Central Controller, or with the same multiplexed hardware as a stand-alone or master/slave system where the functional power and complexity afforded by the PCM Central Controller are not required. The solution to the configuration control problem is to have a 'hands-off' data acquisition system with all variables of the signal conditioning and PCM encoding functions under software control. In one concept, this includes functions such as instrumentation amplifier gains and offsets, presample filter knee selection, a common gain programmable amplifier with programmable offsets, and randomly addressable multiplexers with a PCM Central Controller that can store multiple data cycle maps. With all of the variable functions of the system under software control, system configuration can be determined automatically during pre- and post-flight test from a portable ground test set that produces a hardcopy printout of the system configuration. This system concept is being augmented by increasing sampling rate capability up to 500k sps for processing vibration/acoustic data. Fiber optical communications are available between the PCM Central Controller and the remote signal conditioners and multiplexers to provide immunity from extremely high common mode plateaus between subsystem elements located in different parts of a composite materials airframe. This next generation data system is being developed for general purpose flight and ground test applications.
    • Space Flight Operations Center Local Area Network: Hardware Design

      Goodman, Ross V.; Jet Propulsion Laboratory/California Institute of Technology (International Foundation for Telemetering, 1988-10)
      The existing Mission Control and Computer Center at JPL will be replaced by the Space Flight Operations Center (SFOC). One part of the SFOC is the Local Area Network-Based Distribution System. The purpose of the Local Area Network (LAN) is to distribute the processed data among the various elements of the SFOC. The SFOC LAN will provide a robust subsystem that will support the Magellan launch configuration and future project adaptations with the following capabilities: * A proven cable medium (Ethernet) as the backbone for the entire network, with capability for migration to a fiber optics backbone in the future. * Choice of hardware components that are reliable, varied, and supported by companies that are following the growth path of the ISO model (OSI Standards). * Insure a reliable and maintainable network for SFOC-supported projects. * Accurate and detailed documentation of the LAN, valuable for fault isolation and future expansion of the network. * Proven network monitoring and maintenance tools.
    • Spaceborne Recording Systems for the Space Station Era

      Muench, Jerry; Odetics, Inc. (International Foundation for Telemetering, 1988-10)
      A detailed review of spaceborne magnetic tape recorder technology from the late 1970s to the Space Station era is presented. Background information indicates the oft maligned space tape recorder has continued to demonstrate improving reliability since the marginal performances throughout the 1960s. Specifically, the SPOT recorder is reviewed in technical detail to show evolution through LANDSAT 6 and 7 versions, JERS-1, and finally the proposed ultimate version for Space Station/EOS. Enabling technologies include active tape tracking, magnetic recording head advances, and extensive use of ASIC devices to reduce the EEE piece part count. Suitability of the proposed Space Station/EOS recorder technologies for even more advanced future applications are discussed with data rates to 1 Gbps and storage capacities to 1 X 10¹² bits.
    • Spacecraft Telemetry Tracking State of the Art and Trends

      Mayer, Gerhard; DFVLR Applied Data Syst. Div. (International Foundation for Telemetering, 1988-10)
      Telemetry Tracking is a method of obtaining trajectory information regarding any flying body such as an aircraft, missile, satellite, balloon or a deep space probe which signals or "marks" its flight position by an electromagnetic radiating source. In a trade-off of costs it is an attractive way to combine Telemetry, Tracking and Command (TTC) facilities into one integrated system on board a spacecraft and with the ground receiving and tracking facilities. The present state of the art of Distance Measuring Equipment (DME) and Angle Measuring Equipment (AME) integrated with telemetry systems is reviewed. The further development will be mainly stimulated by the technology evolution of frequency and time reference sources, microwave components and information processing systems. An attempt is made to analyse which way the growth of technology will influence various system parameters.
    • Static RAM Data Recorder for Flight Tests

      Stoner, D. C.; Eklund, T. F. F.; Sandia National Laboratories (International Foundation for Telemetering, 1988-10)
      A static Random Access Memory (RAM) data recorder has been developed to recover strain and acceleration data during development tests of high-speed earth penetrating vehicles. Bi-level inputs are also available for continuity measurements. An iteration of this system was modified for use on water entry evaluations.
    • A Survays On Fading Channel Over West - Java Area for Flight Test Radio Telemetering Purposes

      Soelaiman, Adi Dharma; Pudjiastuti, Rina; Indonesian Aircraft Industry Ltd. (International Foundation for Telemetering, 1988-10)
      This paper discusses one approach to determine a characteristic of West - Java's air and ground segment as a block-box to accomodate radio waves propagation, especially in L-band ranges, by evaluating both the topographical data and radio reception pattern as measured from ground based telemetry receiving-end system. All the measured signals are random and assumed to be stationair and ergodic. In order to characterize the channel for polarization diversity reception, some statistical analysis are applied to the signal strength measured of both - RHCP and LHCP components of 1531 MHz propagated waves as transmitted fr om NC212-200 PK-NZJ-aircraft. Some computer calculated correlograms of measured data are shown herewith, it is focused for a certain radio corridor at radial 265E relative to the ground based receiving antenna. More over some curves of predicted multipath gain factor are also presented to gain more theoretical back ground. When this paper is written, a further field experiments on the matter concerned is beeing conducted.
    • A Symmetric Telemetry Diversity Combiner System

      Busch, Charles E.; Fernandez, Jose M.; Scientific-Atlanta, Inc. (International Foundation for Telemetering, 1988-10)
      Phase-tracking discontinuities produced by switching transients in the usual Master/Slave telemetry diversity combiners under deep-fade conditions, can create data loss in modern, phase-modulated telemetry systems. This paper presents an innovative, dual-channel diversity combining system that overcomes this deficiency, has improved phase noise performance, and maintains full optimal ratio combining for PM, FM, and PSK modulated PCM telemetry. This is accomplished by a symmetric architecture that does not rely on either of the two input channels as a master reference to which the other is phase locked. The new design has the added advantage that the phase noise of a weak master channel is not superimposed on a stronger slave channel.
    • System Aspects of Digital Video Telemetry

      Deutermann, Alan R.; Randall, Neil C.; Delta Information Systems, Inc. (International Foundation for Telemetering, 1988-10)
      This paper describes a completely integrated digital video telemetry system and analyzes several critical aspects of that system. The typical video network may consist of video source signals on the ground as well as airborne while the receive site is usually ground based. Examples of system issues which will be described and analyzed are listed below. * Multi-mode operation: It is likely that a single receive site must be able to rapidly switch between video sources having different bit rates and modes of operation. One technique to achieve this capability will be presented and discussed. * Error sensitivity: It is important that the coding compression technique be resilient to transmission errors. Techniques to achieve this robustness for both synchronization and data signals will be discussed. * Data Multiplexing: From a system point of view, it is extremely efficient to multiplex other digital signals (e.g. audio, IRIG time code) with the video signal to form a single stream for encryption and transmission. A particularly efficient multiplex technique will be presented. * Diagnostics: Video telemetry systems are more effective when they contain carefully designed built-in diagnostics. Advanced concepts for both board-level and system-level diagnostics will be presented.
    • A System Conforming to the New IRIG Standard for Processing MIL-STD-1553 Data

      Payne, David; O'Brien, Mike; Fairchild Weston Systems Inc. (International Foundation for Telemetering, 1988-10)
      The typical aircraft development program of the 1990's will use multiple airborne MIL-STD-1553 Data Busses to provide control of the avionics subsystems. These programs have created a need to process data from these busses in a standard format. This format is proposed for Chapter 8 of the IRIG-106 document. This paper describes EMR's MIL-STD-1553 PROCESSING SYSTEM to acquire and process data in accordance with this new standard. This fully integrated and already available system consists of two basic elements: * An All-Bus Instrumentation System(ABIS). * A Ground Processing Station (GPS). The ABIS monitors the MIL-STD-1553 airborne communications busses, and formats all data in a standard IRIG serial PCM stream suitable for on-board recording and/or real-time transmission on a radio link. Each ABIS will handle all data from one to eight busses. The GPS provides both real-time display and post-flight processing of data captured by the ABIS.
    • Tape Certification Today and in The Future

      O'Sullivan, Tony; Book, Harold; BOW Industries, Inc. (International Foundation for Telemetering, 1988-10)
      The advent of high density digital recording has required the development of sophisticated tape certification equipment which allows the user to test tape for dropouts at his actual system bit packing density and to clean and program wind tapes with the same equipment. By using two sets of reproduce heads with dual threshold and duration controls tapes can be graded as to their suitability for use with HDDR systems or far less exacting analog applications.
    • Telemetry Chart Recording Via Direct Digital Link

      Smith, Grant M.; Alexander, James H.; Astro-Med, Inc. (International Foundation for Telemetering, 1988-10)
      Mission safety and cost-efficiency concerns have resulted in a resurgence of interest in real-time strip chart recorders. But conventional recorder technologies require inordinate maintenance and daily calibration. Attempts at strip chart emulation involving costly dedicated microcomputers and CRT's have failed, because the chart itself is not real-time, a basic requirement. The concept of an inexpensive, direct digital link to a telemetry processing computer (VAX, e.g.) is discussed. A thorough examination of real-time monitoring of critical, non-repeatable data is presented. Objectives: An automated, turn-key telemetry data system. Reduce the routine maintenance required by conventional recording systems; eliminate the need for digital-to-analog converters (DAC's); and improve the efficiency of range personnel and the integrity of recorded data.
    • Telemetry Data Processing: A Modular, Expandable Approach

      Devlin, Steve; Aydin Monitor Systems (International Foundation for Telemetering, 1988-10)
      The growing complexity of missle, aircraft, and space vehicle systems, along with the advent of fly-by-wire and ultra-high performance unstable airframe technology has created an exploding demand for real time processing power. Recent VLSI developements have allowed addressing these needs in the design of a multi-processor subsystem supplying 10 MIPS and 5 MFLOPS per processor. To provide up to 70 MIPS a Digital Signal Processing subsystem may be configured with up to 7 Processors. Multiple subsystems may be employed in a data processing system to give the user virtually unlimited processing power. Within the DSP module, communication between cards is over a high speed, arbitrated Private Data bus. This prevents the saturation of the system bus with intermediate results, and allows a multiple processor configuration to make full use of each processor. Design goals for a single processor included executing number system conversions, data compression algorithms and 1st order polynomials in under 2 microseconds, and 5th order polynomials in under 4 microseconds. The processor design meets or exceeds all of these goals. Recently upgraded VLSI is available, and makes possible a performance enhancement to 11 MIPS and 9 MFLOPS per processor with reduced power consumption. Design tradeoffs and example applications are presented.
    • Telemetry Processing - Realtime to Postflight

      Quesenberry, Dave; Reed, Gary; CSC Network Systems Division (International Foundation for Telemetering, 1988-10)
      The Test Support Facility Integrated Flight Data Processing System (TSF IFDAPS) has recently been developed and installed for the Air Force at Edwards AFB. The TSF IFDAPS incorporates a number of new capabilities designed to satisfy today's advanced requirements for high performance and flexible telemetry processing. This paper describes some of the advances accomplished by the TSF IFDAPS.
    • Trends in Telemetry Systems

      Strock, O. J. (Jud); Fairchild Weston Systems, Inc. (International Foundation for Telemetering, 1988-10)
      This tutorial is an examination of trends in telemetry systems as we approach the 1990s. . . a look at where we are, and where we appear to be headed in the near future. Historically, the typical change in our technology is brought about by one of three conditions. First, users demand performance improvements in order to facilitate their analysis of test programs. Second, manufacturers make performance improvements because continuing advances in component technology enable them to offer improved products for telemetry applications. Third, developments in non-telemetry applications, both hardware and software, are adapted to our needs by system designers. We will see the results of all three conditions as we look at trends in telemetry systems.
    • uDACS Micropackaged Data Acquisition and Control System

      Sodini, Gregory L.; SCI Technology Inc. (International Foundation for Telemetering, 1988-10)
      The miniaturization of Aerospace Systems, has created a demand for effective, compact, lightweight, and power efficient General Purpose Stand-Alone Flight Computers, as well as Command, Data Handling and Control Systems, that maintain High Reliability, Full Redundancy, Radiation Hardness, Explosive Processing Speed, Rapid Throughput, and High Accuracy. The innovative design techniques used in the uDACS (Micropackaged Data Acquisition and Control System) offer a unique and comprehensive solution to this quandary.
    • The Use of Databases in Telemetry Processing Systems

      Massing, James E.; Fairchild Weston Systems Inc. (International Foundation for Telemetering, 1988-10)
      The amount of information necessary for a computer to setup and process data through a telemetry system is increasing rapidly, The complexity and number of telemetry formats often requires a variety of front-end setups to be kept in the computer. Also, as hardware preprocessors become more common, there is a need to maintain in the computer all information used to direct real-time processing of individual parameters. The need for storage of those setups and parameter definitions, and rapid retrieval of this information, has led to the use of databases in well-designed telemetry systems.
    • Utilization of Real Time Digital Strip Chart Emulation (RTDSCE) Concepts

      Halsey, Tim; Brimbal, Michel; Grottenthaler, Gary; Gould Incorporated (International Foundation for Telemetering, 1988-10)
      "Real Time Digital Strip Chart Emulation", a paper presented in the 1987 ITC Proceedings is reviewed for continuity and the digital techniques applicable to range data display are expanded upon. The paper seeks to present the process of recording telemetered signals in the RTDSCE data management scheme. Direct hardware interfacing is discussed with emphasis on automation and manpower reduction. Time code display and various mass storage possibilities are explored. The merits of video monitoring and the workstation concept during playback are evaluated.