• Reaction Torque Minimization Techniques for Articulated Payloads

      Kral, Kevin; Aleman, Robert M.; Honeywell-Sperry Space Systems; Goddard Space Flight Center (International Foundation for Telemetering, 1988-10)
      Articulated payloads on spacecraft, such as antenna telemetry systems and robotic elements, impart reaction torques back into the vehicle which can significantly affect the performance of other payloads. These disturbances can degrade the quality of the data obtained by other on board experiments and systems. This paper discusses ways to minimize the reaction torques of articulated payloads through command shaping algorithms and unique control implementations. The effects of reaction torques encountered on the LANDSAT satellite are presented and compared with simulated and measured data of prototype systems employing these improvements.
    • Realtime Telemetry Processing System (RTPS) III: A Preview of Software Development in the 1990s

      Hill, Jerry L.; CSC Network Systems Division (International Foundation for Telemetering, 1988-10)
      Software development is becoming less an art form and more an engineering discipline. Methods of software development which leave as little as possible to chance are constantly being sought and documented. However, the gap between what is written and what is actually applied is usually quite wide. The only way this gap can be narrowed is through practical application of these very detailed and complex methods. Since it is unlikely that the complexity of these methods will be reduced, automation must be employed wherever possible in the software development process. This paper addresses the successful development of software for the Navy's Realtime Telemetry Processing System III (RTPS III) using practical application of existing methodology in conjunction with a Computer Aided Software Engineering (CASE) tool. Based on this experience, the conclusion presents implications affecting software development the 1990s.
    • Receiver/Combiner for Shipboard Telemetry Applications

      Baker, Thomas G.; Lennox, William M.; Naval Surface Warfare Center; Microdyne Corporation (International Foundation for Telemetering, 1988-10)
      Improvements in the performance and electronic sophistication of Navy missiles require concurrent improvements in telemetry reception. The Microdyne 2800 Receiver/Combiner, developed for the Naval Surface Warfare Center (NSWC), provides an improved shipboard receiving capability to meet this requirement. The Microdyne 2800, or "2800", is a dual channel diversity combining telemetry receiver, which, though designed to meet the unique Navy shipboard environment, provides a capability previously available only with large shore based receiving systems.
    • Reliable Solid State Data Storage Device for Spacecraft T&C Subsystems

      Capots, L.; Chitty, R.; Ameti, A.; Mitchell, W.; Fairchild Space Company (International Foundation for Telemetering, 1988-10)
      Fairchild Space Company, a division of Fairchild Industries, has developed an advanced data recorder based exclusively on the use of Solid State circuitry for the recorder memory. This paper describes the recorder, its development, the engineering considerations for long-term mission life, methods for minimizing size, weight and power, and the flexibility of the recorder to accommodate a number of different mission requirements. Unlike the more traditional mass storage devices for spacecraft, which use rotating memory, the Solid State Recorder (SSR) uses a true random access memory. This feature has resulted in a multi-mode storage device, which can greatly reduce the complexity of spacecraft data systems. Today's spacecraft have large numbers of sensors and high rate instruments which are making the data flow problem much more difficult to handle. Bottle necks also referred to as "data fusion" have become a serious problem for systems engineers, for which the SSR may represent an effective solution. The paper concludes with a discussion of some system applications which illustrate the broad range of possible SSR applications, and the development status.
    • Research and Recommendation of Optimum Group Synchronization Codes for N = 7 -- 32

      Zhongkui, Lei; Qiucheng, Xie; Jie, Cao; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      In this paper, based on a series of research achievements [2,3,4,5,6], are examined the "The Optimum Frame Synchronization Codes" provided by J. L. Maury Jr. and F. J. Styles for IRIG Telemetry Standards USA, and furthermore, recommended a set of Optimum Group Synchronization Codes for China Telemetry Standards.
    • RF Hybrid Linear Amplifier Using Diamond Heat Sink

      Karabudak, Nafiz; Aydin Vector Division (International Foundation for Telemetering, 1988-10)
      This paper will address the applications and methods used for a high power output RF linear small signal amplifier using diamond heat sink. Comparison and the benefits of using diamond heat spreaders will be reviewed. Agrowing number of researchers, engineers and scientists are looking into the applications of diamond's unique properties such as physical, electrical and optical.
    • Ruggedized Television Compression Equipment for Test Range Systems

      Gattis, Sherri L.; Naval Weapons Center (International Foundation for Telemetering, 1988-10)
      The Wideband Data Protection Program was necessitated from the need to develop digitized, compressed video to enable encryption.
    • S-Band Phased Array Antenna for the E-9A

      Cooke, William P.; Burdette, Lawrence; Zoledziowski, Severyn; Hatcher, Glenn; Georgia Institute of Technology; LTVMEG; Eglin Air Force Base (International Foundation for Telemetering, 1988-10)
      This paper describes the requirement, design and test results for the Airborne Phased Telemetry Array for the E-9A Airborne Platform.
    • The Searching Method of Optimum Frame Synchronization Codes Based on the Synthetic Optimum Criterior

      Jie, Cao; Qiu-Cheng, Xie; Nanjing Aeronautical Institute (International Foundation for Telemetering, 1988-10)
      This paper gives a new searching criterior of optimum or suboptimum frame sync codes that escapes from unnecessary calculation and presents a searching method. It has a great improvement on existing methods (exhaustion technique, and so on) and the computing time is decreased by 1~2 order of magnitudes. Finally, the optimum frame sync codes with the length n from 7 to 32 are given.
    • 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.