• SOFTWARE IN DRONE CONTROL

      Shaver, Robert L.; Sandia National Laboratories (International Foundation for Telemetering, 1981-10)
      High performance multi-use drones require complex control capability. Distributing the communications, control and navigation functions among different microprocessor systems connected in a network improves performance and reliability. Assembly language provides the means of optimizing time critical functions of communications and I/O control, which high level languages, such as PASCAL, ease development of mission management requirements. The use of real-time operating systems (RTOS) permits co-processing of a variety of functions in overall drone operation management. The RTOS is a software “bus” providing communications network for modules. Functions and modules are assigned priorities, enabled or suspended as needed to perform mission operational requirements via the RTOS.
    • NETWORK SUPPORT OF TDRSS

      Smith, Cassius C.; TRW White Sands Ground Terminal (International Foundation for Telemetering, 1981-10)
      The Tracking and Data Relay Satellite System (TDRSS) is controlled by a local computer network of nine Digital PDP-11/70s and a Univac 1100/82. Distributed processing of specific software tasks provides for high-speed response to time critical loop support, as well as increased reliability and flexibility of the overall system. Man-machine interface, spacecraft monitor/control and computer failover is supported by the distribution of tasks to specific computers within the network. Altogether, the network support of TDRSS makes possible tremendous increases in capability over conventional satellite ground stations.
    • VIDEO BASED INSTRUMENTATION SYSTEMS AND TECHNIQUES FOR MERGING DATA INTO VIDEO

      Keller, P.; Naval Weapon Center (International Foundation for Telemetering, 1981-10)
      A need is shown for the development of standardization in data into video encoders and decoders for instrumentation systems. Features such a standardized system should have are listed and discussed based on the authors experience with video instrumentation systems at the Naval Weapons Center and as a consultant.
    • ADVANCED 14/12 AND 30/20 GHz MULTIPLE BEAM ANTENNA TECHNOLOGY FOR COMMUNICATIONS SATELLITES

      Chen, C.C.; TRW Defense and Space Systems Group (International Foundation for Telemetering, 1981-10)
      This paper discusses recent TRW advances in communications satellite antenna technologies for the 14/12 and 30/20 GHz bands. The 14/12 GHz antenna system provides 15 or more high gain, low sidelobe spot beams for contiguous coverage of the CONUS for point-to-point communications, or four contoured time zone beams for direct broadcast service. A 2-meter offset reflector has been built and tested to demonstrate the frequency reuse and beam isolation capabilities of the antenna. The 30/20 GHz antenna system provides 10 to 20 fixed beams for large volume traffic trunking service and six independently scanned beams for customer-premise-service within the CONUS. A proofof- concept model antenna for proving the technology feasibility is currently under development.
    • SYSTEM ASPECTS OF SCANNING BEAMS FOR WIDELY DISTRIBUTED USERS

      Kolba, Dean P.; M.I.T. Lincoln Laboratory (International Foundation for Telemetering, 1981-10)
      Satellite communications in the allocated EHF bands, (i.e., several frequency segments from ~20 GHz to 50 GHz) has the potential for providing interference resistant communications to users employing small, mobile terminals. To realize this potential, advanced spacecraft technologies are required, such as uplink coverage through high gain directive beams, onboard signal processing, and downlink beam hopping. Simultaneous worldwide uplink coverage could be obtained via many narrow uplink antenna beams which collectively cover the earth field-of-view. When worldwide communications traffic is low volume, a reduction in space segment impact can be achieved by using a few narrow uplink antenna beams to provide the required service. To minimize delays, these beams must be able to rapidly point anywhere within the field-ofview to cover individual users who require a channel for brief communications. The agile antenna beams can be shared through demand assignment techniques. A multimode common transmission format can provide both data and control channels. The data channels are available at several rates to allow either full duty cycle data transmission or burst data transmission. With burst transmissions, a single beam can support multiple calls in a time division multiplexed fashion. The control channels are utilized in coordinating the use of satellite resources to efficiently meet the communications needs of the users. This paper discusses the use of EHF satellite communicatons to provide service to widely scattered users. The use of control channels to request and coordinate service is described. Example control protocols are presented, and system performance is indicated.
    • SPACE RADIATION HARDENING AND VLSIC TECHNOLOGY

      Josephson, Vernal; The Aerospace Corporation (International Foundation for Telemetering, 1981-10)
      Military Space Systems are required to have a certain level of immunity to all possible space radiation effects experiences during mission life time. These include upset and latchup from weapon x-ray bursts and cosmic rays, photo current burn-out of active junctions by large prompt doses of radiation, and performance degradation from accumulated dose due to enhanced radiation belts. Procuring piece parts capable of performing mission requirements and providing the desired immunity to these effects, and testing to verify the desired satellite immunity presents problems which must be considered when contemplating massive use of VLSIC technology where even higher desired levels of immunity may be desired. The techniques used for hardening and the testing required for hardness assurance will be discussed with emphasis on their application to VLSIC technology and its potential in space applications. An overall satellite was subjected to irradiation in order to verify its immunity to space radiation. These results will be discussed below.
    • VARIABLE DATA BIT RATES WITH A FIXED HOP RATE NONCOHERENT FH/MFSK SYSTEM

      Omura, Jim K.; School of Engineering and Applied Science Los Angeles (International Foundation for Telemetering, 1981-10)
    • TELEMETRY SOFTWARE DEVELOPMENT LIFE CYCLE

      Campbell, Alan B.; ABC Systems, Inc. (International Foundation for Telemetering, 1981-10)
      All orderly software development proceeds through the phases of a predictable life cycle. This behavior is characteristic of telemetry software development, also. Each phase of the life cycle is definable in terms of specific milestones. Understanding the life cycle is crucial for accurate estimation of time and effort, as well as for producing reliable software on time and within budget.
    • COMMUNICATIONS FOR THE ESA GIOTTO (COMET HALLEY ENCOUNTER) MISSION

      Wasse, Michael P.; European space Technology Centre (International Foundation for Telemetering, 1981-10)
      This space mission will investigate the structure of the comet by passing close to the nucleus. The spacecraft will first be injected into a geostationary transfer orbit where a perigee boost motor will deliver the kick necessary to encounter the comet post perihelion, as it passes through the ecliptic plane at a distance of 0.98 AU from the earth. The spinning spacecraft and the use of a shield for protection from the dust present in the comet atmosphere dictate the use of a despun high gain antenna with inclined beam. The telemetry downlink at 40 KBps is in X Band and will be received on the Parkes (Australia) radio telescope which will be specially adapted for the task. The trade offs leading to the selected communications configuration are described along with the various spacecraft hardware items such as antennas, transponder, decoder and twta.
    • ULTRA LIGHTWEIGHT, LOW COST, TELEMETRY TRACKING SYSTEM

      Sullivan, Arthur; Electro Magnetic Processes, Inc. (International Foundation for Telemetering, 1981-10)
      Because of limited budgets, many telemetry applications can not be performed on a real time basis. Consequently, there is a need for a very low cost tracking system. In addition to being inexpensive, the system should be lightweight to minimize building or tower modifications required for installation, and to lower shipping and handling costs. In order to reduce weight and cost, EMP, Inc. has designed an aerodynamically smooth single axis tracking system with a multimode antenna, constructed almost entirely of graphite and utilizing a minimum number of parts. Using this material, the system will be as strong as a conventional system, but will be one half the weight and will be almost temperature insensitive. Furthermore, with the construction technique selected, considerable savings are realized in fabrication costs. Additionally, the step -track technique via a microprocessor controller was selected to eliminate the expensive autotracking feed and all the associated electronic circuitry required for high performance angle tracking. Since a single axis tracking system with a multi-mode antenna can cover a wide variety of missions, an elevation tracking axis is not required. In-close and near overhead passes are covered by the low gain antenna. Switching between the antennas is accomplished automatically based on received signal strength.
    • WWMCCS SPACE ASSETS; CONTRIBUTORS TO A TOTAL SYSTEM

      Coyle, James; The MITRE Corporation (International Foundation for Telemetering, 1981-10)
      This paper outlines the roles of satellite systems in the context of the overall WWMCCS mission. It describes the types of operational interdependencies that exist between ground elements and the satellites of space systems and proposes that, because of these interdependencies, equal consideration of the survivability of ground elements must be included in system planning in order to capitalize on the contribution of space assets to the WWMCCS mission.
    • INSTANTANEOUS FIBER OPTIC VISICORDING OF HIGH INTEREST/HIGH FREQUENCY DATA

      Calandrino, Peter; Calandrino Electronic Systems (International Foundation for Telemetering, 1981-10)
      The ability to display, expand, time frame select, and permanently record data of high interest/high frequency over long time periods provides the capability to analyze data in near real time and provide immediate responses to laboratory or remote platform/onboard system problems. Many recording techniques provide large recording bandwidths, but do not also provide an immediate hard copy readout from which early decisions can be made. A wider bandwidth capability can expand the already large spectrum of visicorder uses. This paper describes a new high speed recording capability which involves the introduction of an x/y converter/fiber-optic visicorder system into a telemetering link that can record one MHz data for long periods of time, together with time frame selection capability. The system can provide line continuous monitoring of high interest data.
    • THEORETICAL AND PRACTICAL ASPECTS OF OPTIMIZATION IN FINITE WORD-LENGTH DIGITAL SIGNAL PROCESSING

      Pollara-Bozzola, F.; Yao, K.; Univ. of California (International Foundation for Telemetering, 1981-10)
      We consider a general class of digital signal processing problems in which some sytem parameters restricted to some finite set of values are selected based on the minimum meansquare error criterion. This class of problems are relevant in the design of modern communication, radar, and antenna array systems under finite word-length con-constraints. Linear problems allowing infinite precision values are given by the classical Wiener solutions. However, under the finite word-length constraints, optimum solutions can be obtained in principle by using techniques from integer quadratic programming problems. Practical solutions obtained in this manner, such as from the branch-and-bound algorithm, usually use a large amount of active computer memory space and thus are not applicable to real-time on-board processing situations. In this paper, we shall consider various theoretical and practical aspects of exhaustive search algorithms over shrinking sequences of constrained regions known to contain the desired optimum solution. Properties and bounds on the number of points to be searched as well as specific system problems shall be presented.
    • A PROGRAMMABLE-SIGNAL CONDITIONING PULSE CODE MODULATED TELEMETRY ENCODER

      ECKSTEIN, HOWARD M.; MICROCOM CORPORATION (International Foundation for Telemetering, 1981-10)
      The development of variable format airborne PCM data acquisition systems has generally been predicated upon advances in the field of solid state memory device technology. The introduction of Electrically Eraseable Programmable Read Only Memory (EEPROM) devices has generated renewed interest in the design of fully programmable PCM encoders. This paper will describe the evolution of one such micro-miniature PCM encoder system incorporating the following features: ∙ Complete Frame Format Program Capability ∙ Software Controlled Single Ended/Differential Input Program Capability ∙ Individual Sample - Gain/Offset Scaling Capability ∙ Hard Wire Program/Erase/Program Capability ∙ Variable Word Resolution ∙ Small Size
    • ACCURATE ANTENNA REPOINTING FOR PATTERN MAPPING

      HOLTZ, L. VAN; European Space Research & Technology Center (International Foundation for Telemetering, 1981-10)
      The attitude control system of the European Space Agency’s Orbital Test Satellite (OTS) was originally designed for nominal earth pointing with only limited bias capability (of up to 2.5° in pitch and roll) which is more than adequate to remove earth sensor/wheel misalignments that could be incurred during or following launch. Subsequently, a need was expressed to support off-nominal coverage missions and antenna mapping tests. A method was thus defined that would provide greater repointing capability (up to 4.6°) while retaining the accuracy available with the precision infrared sensor. The method is outlined, and the repointing limitations indicated that are inherent to the OTS sensor design (13° in roll and 7° in pitch). Operations and conditions are stated that enable these extremes to actually be reached. The error budget is presented for the case of antenna mapping, demonstrating that attitude restitution can be made so that beam centre position can be determined to an accuracy of 0.1° half cone angle. The significant advantages of the described method are that only one ground station is required, and that results can be available within 24 hours following completion of the test. Results obtained with OTS are referred to, that support the claims. Finally desirable design modifications are discussed that could allow further increases in repointing capability of future satellites.
    • A METEOROLOGICAL COMMAND AND CONTROL SYSTEM

      P. L. Greening; Kinney, T. W.; Shaw, T. R.; HARRIS CORPORATION (International Foundation for Telemetering, 1981-10)
      There are many functions required to command, control and maintain the health and welfare of a meteorological satellite and acquire payload sensor data in a real time scenario. This paper describes the functions and performance of a specific meteorological command/control and telemetry processing system. Further, this paper describes the communications networks which link the various command/control, telemetry, and user ground stations together. A description of the user sensor data is also presented.
    • A HIGH-PERFORMANCE ERROR CORRECTION SYSTEM FOR DIGITAL TAPE RECORDERS

      Kessler, W.D.; Stein, J.H.; Sangamo Weston, Inc. (International Foundation for Telemetering, 1981-10)
      An erasure type error correction system for parallel high density digital tape recorders is described. The system can correct for error bursts of any length occuring on either single tracks or any two tracks simultaneously. Calculations of theoretical performance are compared with measured performance and a figure of merit for error correction systems is used to compare typical systems.
    • International Telemetering Conference Proceedings, Volume 17 (1981)

      International Foundation for Telemetering, 1981-10
    • THREAT-RESPONSIVE SURVIVABILITY AND SPACE WARFARE AT HIGH ALTITUDES

      McPherson, Donald A.; Science Applications (International Foundation for Telemetering, 1981-10)
      The US is being denied effective use of space systems for tactical support of combat operations because of doubts regarding the survivability of space missions in hostilities. Space systems survivability has been the object of widespread analysis and development for fifteen years. Because survivability is expensive, the decision to make the necessary substantial investments for high-altitude satellites will be postponed until there is tangible evidence that the threat is developing into anti-satellite weapon systems. Therefore, space system development and acquisition must be formulated so that the appropriate survivability investment can be made as the physical attack threat at high altitudes eventually emerges.
    • DIGITAL DATA IN VIDEO PROCESSING SYSTEMS

      Morse, Bob A.; BELL TECHNICIAL OPERATIONS (International Foundation for Telemetering, 1981-10)
      Digital information in video systems is an expanding field. The use of digital video equipment is continuously being examined and updated at USAYPG. There are fully operational systems currently being used by BELL TECH. OPS at the proving ground. I shall cover some of the uses and capability of the systems as well as the individual pieces of equipment in the systems