• AN OVERVIEW OF CONFORMAL ANTENNA DESIGN TECHNIQUES USEFUL FOR TELEMETRY APPLICATIONS

      Jones, Howard S., Jr.; Formerly with Harry Diamond Laboratories (International Foundation for Telemetering, 1982-09)
      Several conformal antennas useful for telemetry applications are described. These antennas make use of dielectric-loaded cavity, edge-slot, microstrip, and dielectric rod radiator design techniques. Critical design parameters, modes of radiation, and theoretical considerations are discussed, as well as intrinsic properties and characteristics of the dielectric materials used. Experimental data relating to impedance, gain, polarization, and bandwidth are given. Also presented are prototype telemetry antennas and performance characteristics. The conformal antennas are flushmounted and designed as an integral part of the body structure. These antennas are electrically small and compact, occupying minimial space. They can be designed efficiently for operation in the telemetry frequency band to produce the desired radiation pattern coverage. Simplified construction and low cost are among the other advantages realized.
    • MODULAR TELEMETRY SOFTWARE FOR REAL-TIME APPLICATIONS

      STROCK, O.J.; Data Systems Division Sangamo Weston (International Foundation for Telemetering, 1982-09)
      A modular software system, operating in conjunction with unique direct-memory-access hardware modules, provides control of real-time high-speed telemetry data entry, storage, processing, and display in any of a family of small general purpose minicomputers. The software operates with engineer-language commands.
    • SYSTEM DESIGN METHODOLOGIES

      Kelly, Mike; Sangamo Weston, Schlumberger (International Foundation for Telemetering, 1982-09)
      This purpose of this paper is to show how structured programming methodologies, used in the design and development of computer programs, can and should be used in the design and development of telemetry systems. One important concept presented in that of thinking of the telemetry system as a complete system from the very beginning such that a total system design can evolve “naturally”. Many of the problems associated with telemetry systems today are due to the fact that the various “pieces” of the system were designed independently and without regard for each other. Also discussed are the various levels of documentation produced along with Engineering and Marketing responsibilities as they relate to systems design.
    • A DROPOUT BASED ERROR CORRECTION METHOD FOR USE ON DENSITY DIGITAL RECORDING SYSTEMS

      Meeks, Leighton A.; Honeywell, Inc. (International Foundation for Telemetering, 1982-09)
      Honeywell has developed and reduced to practice, a variation of the check word approach to error detection and correction for use on multi-track parallel high density digital recording systems. Implemented on the Company’s Model HD-96 systems, this method takes advantage of the high degree of correlation of bit errors with tape signal dropout intervals. A signal dropout detector is provided on the reproduce side for each digital data track to replace the check word at the end of each channel encoding frame. This dropout method has the advantage of reducing buffer memory size required to utilize the check word method. In a previous paper*, the results of a tape signal dropout investigation were reported. In this current paper, details considered critical to successful implementation are described. In addition, sample results from production systems are included.
    • AUTOMATED CONTROL OF MULTIPLE GROUND VEHICLES

      Rice, William A.; National Range Operations Directorate (International Foundation for Telemetering, 1982-09)
      The Drone Formation Control System (DFCS) was developed by IBM, Federal Systems Division in 1976 under contract to the US Army White Sands Missile Range (WSMR) to provide precise automatic closed-loop control for multiple target aircraft. The unique DFCS distance measuring equipment (DME) data link allows for both range measurement and the transmission of both command and telemetry data on a single frequency (915 MHz). The DFCS is controlled by a federated chain of microprocessors linked to a large scale IBM System 360 Model 75. The unique data link embedded in a system totally driven by software allowed the DFCS to be modified for automatic control of multiple ground targets as well as aerial targets. This paper briefly describes the DFCS and the modifications performed for ground target control. The DFCS RF modulation/demodulation technique is emphasized.
    • TRACKING AND DATA RELAY SATELLITE SYSTEM STATUS

      McMullen, Malcolm; Assistant Vice President-Advanced Planning Space Communications Company (International Foundation for Telemetering, 1982-09)
      The Tracking and Data Relay Satellite System (TDRSS) is approaching launch readiness, with operations scheduled to commence in 1983. This paper describes TDRSS including the commercial communications or Advanced Westar (AW) components and the launch, network, and test elements being employed to bring the system to operational readiness for user support. Users and user equipment are also discussed.
    • A MULTI-USER TELEMETRY PROCESSING ARCHITECTURE

      Michaud, Colonel Normand; Hollander, Sidney; Hq Air Force Satellite Control Facility (AFSCF); The Aerospace Corporation (International Foundation for Telemetering, 1982-09)
      This paper updates the previous work,¹ which described the overall telemetry and data processing capabilities of the Data System Modernization (DSM) system being developed at the Air Force Satellite Control Facility (AFSCF). Having passed the System Critical Design Review milestone, the DSM program is proceeding with the design and implementation of various elements which support both the real-time routing, processing, storage, and display of satellite telemetry data, as well as the off-line recall of raw or processed telemetry data for trend analysis and satellite operations planning. A Data Distribution Element routes data received from 13 Remote Tracking Station (RTS) antennas and other sources to dedicated telemetry processing elements located within eight Satellite Test Center (STC) Mission Control Complexes (MCCs), a Range Control Complex (RCC), and the System Development and Test Laboratory (STDL). Two types of telemetry preprocessing elements are provided: one for processing telemetry data of rates less than 32 kilobits per second (or for processing selected measurands from telemetry data of rates up to 1.024 megabits per second), and the other for processing high-rate telemetry up to 5 megabits per second. Computer programs executing within one of two large mainframe computers and a Telemetry Contact Support Equipment Group in each MCC selectively decommutate, compress, calibrate, and store the telemetry data. Once processed, the data is formatted into unique, user-defined displays for real-time or post-contact analysis. Interfaces are also provided to satellite commanding routines for the authentication or verification of commands that have been transmitted to the satellite during the contact. Additional computer programs provide the capability to extract designated measurands from the processed telemetry history files, and format them, into messages for near realtime transmission to users remotely located from the STC. A capability is also provided to interface future telemetry preprocessing equipment, such as that required to support multiple scientific payloads aboard the Space Shuttle.
    • WHITE SANDS MISSILE RANGE (WSMR) A PHASE - DIFFERENCE MEASURING TRACKING SYSTEM

      PARRA, MARIO Z.; National Range Operations Directorate (International Foundation for Telemetering, 1982-09)
      The Phase Difference Measuring (PDM) system is an RF interferometer object tracking system which utilizes the object’s radiated telemetry power spectra for tracking purposes. The PDM system is being developed in-house at White Sands Missile Range as a highly mobile electronic angle measuring system, to augument existing position measuring capability in range instrumentation systems. The system is comprised of two Remote Data Acquisition Stations (RDAS) and a Cosine Conversion Facility (CCF). Each RDAS is comprised of two antenna arrays configured as crossed baselines. The RDAS equipment utilizes high speed RF switching in a time sharing technique designed to reduce the amount of hardware required at the remote sites to produce direction cosines. The CCF collects two direction cosines from each RDAS, it then transforms the direction cosines to position data for subsequent transmission to a Range Control Center. This paper will provide basic system theory, explain the proposed antenna PF switching techniques, and also the computer simulation analysis for a baseline consisting of two pair of antennas.
    • THE EFFICIENT USE OF A VAX COMPUTER IN THE REAL-TIME TELEMETRY ENVIRONMENT

      Robbins, Robert B.; Data Systems Division (International Foundation for Telemetering, 1982-09)
      The use of a Digital Equipment Corporation VAX computer under the VMS operating system, in a real-time telemetry environment, brings with it many advantages. These advantages pertain to its ability to handle real-time telemetry processing in an efficient and relatively straight forward manner. The author will use the TELSET, TELDAX and TELFOR telemetry software systems as the basis for demonstrating the techniques which have allowed the real-time telemetry user to take advantage of a 32-bit, virtual addressing, architecture.
    • DMSP BLOCK 5D-2 SPACECRAFT Telemetry Real-Time Analysis and Display System (TRADS)

      Allen, David L.; The Aerospace Corporation (International Foundation for Telemetering, 1982-09)
    • MX MISSILE IN-FLIGHT VIBRATION DATA PROCESSING

      Baker, George; Martin Marietta Corporation (International Foundation for Telemetering, 1982-09)
      The quantity of measurements and broad frequency spectrum of interest for dynamic measurements required to support the development phase of the MX Missile, in conjunction with a limited downlink telemetry bandwidth, necessitated a unique vibration measurement system. This was accomplished by on-board vibration data processing comprising a sensor system (transducer/ low noise cable/charge amplifier) and a multichannel digital Vibration Data Processor (VDP). The processor is a 1/3 octave frequency band analyzer, employing digital filter circuitry covering 22 bands over a frequency range from 14 Hz to 2245 Hz, providing an output that represents the energy(G²) per band/time interval. A Master Data Control Unit (MU) controls the VDP operation via a full duplex data bus. This paper will describe the sensor system, with its designed in-post installation test/verification features and the capabilities and design features of the VDP. Processor characteristics such as the self-test operation whereby all 1/3 octave analysis bands are verified, the ability to meet a 60 dB dynamic range, the indivudual instructions code capability along with other features will be presented. The most important facet of this onboard processing allows a downlink data bandwidth conservation ranging up to 184:1 which is compatible with the digital telemetering system.
    • PROCESSOR TECHNOLOGY OFFERS UNREALIZED FLEXIBILITY IN TOMORROW’S TELEMETRY GROUND STATIONS

      THOM, GARY A.; AYDIN MONITOR SYSTEMS (International Foundation for Telemetering, 1982-09)
      Today’s state of the art in semiconductor technology coupled with innovative computer architecture techniques can provide tomorrow’s telemetry industry with advanced ground station capabilities. Computer systems have traditionally been used to process all of the telemetry data. As data transmission speeds increase, the computer system can no longer handle real time processing so preprocessors are being used to handle the additional computational requirements. An alternative approach is to embed special purpose processors into applicable elements of the front-end equipment. These processors can be optimized for the function they are to perform, which prevents under utilization of processing power and enhances the flexibility and performance of the front-end element. These special purpose processors take up little real estate when implemented with todays LSI and VLSI semiconductors. The modules which are ideally suited for this type of technology are serial data correlators, decommutators, real time data correction, engineering units conversion, quick look display, data simulation and many special application modules. These processing elements provide the building blocks for a very powerful, cost effective family of modular telemetry and communications products for the 80’s and beyond.
    • WHITE SANDS MISSILE RANGE (WSMR) TELEMETRY TRACKING IMPROVEMENTS

      Pedroza, Moises; White Sands Missile Range (International Foundation for Telemetering, 1982-09)
      The WSMR Telemetry Tracking Systems consist of ten (10) automatic trackers and four (4) manual trackers. These trackers operate in the frequency ranges of 1435 to 1540 MHz and 2200 to 2300 MHz. Two Telemetry Acquisition Systems (TAS) with 24-foot parabolic antennas are located at fixed sites. A 6-foot parabolic antenna system has been converted from a mobile unit to a fixed-site system. Seven Transportable Telemetry Acquisition Systems (TTAS) with 8-foot parabolic antennas can be located on and off the range along with a mobile microwave relay station to support range tests. The RF subsystems on the seven TTAS’s have been miniaturized and integrated with the feed assembly resulting in a vast improvement in autotrack reliability. The digital slave tracking capability of the seven TTAS’s and two TAS’s has been improved by a joint effort between two WSMR organizations. Tracking System Interface (TSI) hardware and software were both developed in-house at WSMR by the Instrumentation Directorate. The National Range Operations Directorate, Data Collection Division, Telemetry Branch interfaced and installed the TSI to the tracking systems. The TSI utilizes two (2) Z80 microprocessors and is capable of slaving to instrumentation RADAR data in one of two modes. The first mode is dependent on the UNIVAC 1108, WSMR real-time computer complex, to convert the RADAR XYZ data to site oriented azimuth and elevation data. The second mode allows the telemetry trackers to accept RADAR XYZ data directly and perform its own coordinate conversion. An additional feature of the TSI is the test mode for self-checks, servo tests, and system readiness tests.
    • POWER COMBINING AND SIGNAL ROUTING IN THE GALAXY TT&C EARTH STATION

      KNOX, K. D.; MALLETTE, L. A.; HUGHES AIRCRAFT COMPANY (International Foundation for Telemetering, 1982-09)
      This paper describes the signal routing and power combining function of the C-band uplink frequency signals in the Galaxy TT&C earth station.
    • A NEAR-OPTIMUM RECEIVER STRUCTURE FOR THE DETECTION OF M-ARY OPTICAL PPM SIGNALS

      Dolinar, Sam; Jet Propulsion Laboratories (International Foundation for Telemetering, 1982-09)
    • KU-BAND COMMUNICATION SUBSYSTEM

      Jarett, Keith; Hughes Aircraft Company (International Foundation for Telemetering, 1982-09)
      The Ku-Band subsystem for NASA’s Space Shuttle Orbiter is a combined radar and communications system that provides either radar-aided rendezvous capability or high-rate two-way communications via a synchronous-orbit TDRS relay satellite. This paper describes the architecture of the Ku-Band system and focuses on several unique aspects of the design. Communication capabilities are described in detail.
    • WIDEBAND MODEM CHARACTERIZATION TESTING

      Finn, Gerald T.; The Aerospace Corporation (International Foundation for Telemetering, 1982-09)
      As part of an investigation into the causes for random, unexplained data “dropouts” on a Defense Satellite Communication link between the Air Force Satellite Control Facility, Sunnyvale, California and the Indian Ocean Remote Tracking Station, a number of tests were conducted to characterize the performance parameters of the wideband modems used on the link. These tests were used to measure the loop parameters of the modem Carrier and Timing Recovery Loops and to determine the modem sensitivity to RF phase disturbances, data rate variations and various repetitive bit patterns. This paper describes the test techniques used and the results obtained.
    • NASA DEEP SPACE NETWORK PERFORMANCE ANALYSIS

      Bartok, Carol DiNolfo; Jet Propulsion Laboratory California Institute of Technology (International Foundation for Telemetering, 1982-09)
      Network performance analysis is an essential element in the operation of the NASA Deep Space Network. The primary function of the Deep Space Network is to support the communication, radio navigation and radio science needs of the flight project users. As a part of Network Control Center Operations, it is the task of the Performance Analysis Group to provide the Network with the analysis support required to assure that actual Network performance meets or exceeds committed levels throughout the mission. The Performance Analysis Group provides time-critical monitoring and analysis for the Tracking, Telemetry and Command Systems of the Deep Space Network. The group is organized into units that are specialized to provide the functional requirements of each system. It provides failure analysis to determine causes of Network failures and data outages, as well as providing technical assistance to the operations organization for recovery from failures. It generates the predictions used to point the antennas, acquire the radio frequency, and to validate the monitored Network performance. Also, it provides technical interfaces with the user projects as required for the smooth running of the operation. As a result of this specialized expertise, complex and time-critical problems that arise receive an immediate decision-making response.
    • TRANSPORTABLE/MOBILE TERMINALS (TMT)

      Sullivan, James F.; Ford Aerospace & Communications Corporation (International Foundation for Telemetering, 1982-09)
      Recent policy statements from senior Air Force personnel places a high priority on the survivability of “deliverable products” from space systems, throughout the conflict spectrum. The timely delivery of these products is dependent on the endurability of the spacecraft, the bit-stream carrying the products, and the ground terminals. Transportable/Mobile Terminals afford a viable option to provide a control segment that can be balanced with the endurability of the space and user segments. This paper examines Transportable/Mobile Terminals whose mission is to provide tracking, telemetry and command support to mission satellites through the conflict spectrum. The role and relationship of TMT’s in the totality of the Satellite Command and Control architecture is discussed in an operational, as well as technical, context. Topics of discussion include threats and countermeasures, sensitivity of design to requirements, the impact of satellite autonomy and the relationship of TMT’s to other planned improvements to the Satellite Command and Control architecture.
    • POLARIZATION DIVERSITY CAPABILITY THROUGH SAMPLING AT THE RF LEVEL

      Endler, Harvey; Turner, William; Electra Magnetic Processes, Inc. (International Foundation for Telemetering, 1982-09)
      Novel RF circuitry for selecting the stronger of two telemetry signals (RHCP or LHCP) is presented. Polarization diversity capability with uninterrupted data flow can be achieved without using two expensive single channel data receivers and a diversity combiner. In certain dedicated systems only a single AM/FM receiver is required. This paper describes the RF signal processing and logic circuitry of a developed system and describes how it is applied in a lightweight polarization diversity single channel monopulse tracking system.