• A Tactical GPS Guidance System

      Gieseking, D. L.; Engel, H. L.; Calibi, V.; Van Dierendonck, A. J.; Hughes Aircraft Company; Magnavox (International Foundation for Telemetering, 1978-11)
      The paper presents results of a design study that defined an optimal (cost vs performance) guidance system that uses the NAVSTAR system. The paper will describe the trades that led to the system configuration. A sequencing receiver (receiver that listens to one satellite at a time) was chosen. This required the navigation system to position the code and frequency of the receiver tracking loops where the receiver switches satellites. Receiver measurements are processed in a U-D formulation of a Kalman filter to update the navigation equations to perform in-flight alignment and parameter estimation of the strapdown gyro biases. Receiver and guidance system performance are presented.
    • TDRSS - User Satellite Acquisition and Tracking

      Franklin, S. B.; TRW Defense and Space Systems Group (International Foundation for Telemetering, 1978-11)
      The Tracking and Data Relay Satellite System (TDRSS) will provide communications and tracking services to the Space Shuttle and most other NASA missions of the 1980's. Relay services are provided between NASA's near earth satellites and a ground terminal at White Sands, N.M. via synchronous Tracking and Data Relay Satellites. Establishing and maintaining the communications links is a complex task which includes spatial, signal and data acquisition involving crosslinks between the TDRS and NASA's user satellites. Concepts and capabilities are presented for antenna acquisition, and for PN code and carrier acquisition. Total acquisition times, including bit synchronizer and decoder acquisition are also provided.
    • TDRSS Multiple Access Receiving Phased Array System

      DuPree, J. E.; TRW Defense and Space Systems Group (International Foundation for Telemetering, 1978-11)
      A 30-element phased array, with remote beamforming and multiple access signal design, is the basis for a new multiple access concept to be used by the Tracking and Data Relay Satellite System (TDRSS). System tradeoffs evolved a control and calibration concept which parallels modern estimation theory in dynamic systems and reduces the complexity of adaptive control while maintaining the necessary accuracy. A system dynamic model propagates "open loop" estimates of optimal weight vectors based on user satellite ephemerides derived from tracking data. A sampled-data closed loop adaptive control system periodically updates the beam-steering vector to eliminate parameter drifts and modeling errors, and to maintain the weight vector near optimum. The concept is primarily useful in the specified noninterference environment, though some nulling capability is possible.
    • TDRSS Telecommunications MA Return Channel

      Weber, C.; Halderman, D.; Blyth, R.; University of Southern California; TRW, Defense & Space Systems Group (International Foundation for Telemetering, 1978-11)
      The Tracking and Data Relay Satellite System (TDRSS) relays signals to and from ground terminal and user satellites. No signal processing is done on the satellite and as many functions as possible have been removed from the satellite and implemented in the ground terminal. The multiple access (MA) users serviced by the S-Band thirty element phased array on the satellite require the capability to form up to twenty simultaneous tracking antenna beams by phase and amplitude weighting the individual antenna elements in the ground terminal. Frequency division multiplexing is used to transmit the 30 antenna elements to the ground for beamforming. Phase and amplitude uncertainties build up over time between the antenna elements and the beam processing on the ground. To optimize and maintain required performance, a calibration technique is required to estimate the channel weight correction table for the MA return link.
    • Technology, Discipline and Future Low Cost TM and Telecommunication Systems

      Seely, Russel B.; Flight Systems, Incorporated (International Foundation for Telemetering, 1978-11)
      Telemetry and telecommunications system costs have become extremely inflated over the past 20 years "needlessly". A unique method for understanding and reducing these system costs is presented, which describes the basic cost factors of simple as well as complex systems, why they are so high and what can be done on a practical basis to drastically reduce them. Two programs are presented to illustrate how the low cost concepts have been used. Finally, a 1-2-3 step-by-step workable approach is offered for use on any type program whether it be space, atmospheric, ground-based, underwater, complex or simple.
    • Telemetry - Past, Present, Future

      Strock, O. J. "Jud"; EMR-Telemetry (International Foundation for Telemetering, 1978-11)
      On the assumption that "the past is prologue", this paper presents an interesting and revealing look at the telemetry technology of twenty years ago, a comparison of that with the technology of today, and an extrapolation into the future of telemetry. Factors which are examined include the characteristics of telemetry systems, the price per unit of performance, and the applications in which telemetry has been, is being, and likely will be used. The key word in the paper is "choice". A user or prospective user had little choice in equipment or techniques twenty years ago; the present day technology offers a wide range of choices; indications are that the future will offer even greater choices in characteristics and price - and consequently, in the applications for which telemetry is a viable tool for data acquisition and processing.
    • Telestream™ - Grumman's Distributed, Parallel Telemetry Processing System

      Gittleman, Michael; McCormick, Raymond; Grumman Data Systems Corp. (International Foundation for Telemetering, 1978-11)
      TeleSTREAM™, the GrummanData Systems Corporation telemetry processor, is a hierarchically arranged combination of hardware, firmware and software which can meet the current and future needs for real time processing of telemetry data. The basic design of the system is highly flexible, allowing application to a wide range of user requirements with a minimum of software changes. The logical flow of input, process, output is accomplished by a distributed processing method utilizing three subsystems: Front End Controllers (FEC's); Task Oriented Processors (TOP's); and Output Processors (OP's). Multiple sources can be processed concurrently, with the FEC's selecting specified data words for processing. Typical telemetry processing tasks are handled by a parallel arrangement of table driven processors (TOP's) utilizing a combination of assembly language and microcoded routines. Output processing routes completed buffers of data to a variety of output devices. Additionally, setup, control, diagnostics and status servicing of telemetry formatting equipment is performed by the OP's. A telemetry compiler allows the user to describe to the system the processing requirements of a particular data source and produces the tables utilized by TeleSTREAM™ to handle the parameters.
    • TIPS - An Integrated Solution for Multi-Mission Telemetry

      Van Dolsen, L. L.; System Development Corporation (International Foundation for Telemetering, 1978-11)
      The Air Force Space and Missile Test Center (SAMTEC) must provide concurrent support for a variety of missions requiring real time telemetry data acquisition and processing. An integrated system is presently going operational to replace seven individual complexes presently supporting these missions. The Telemetry Integrated Processing System (TIPS) includes six real-time input streams, a large-scale near-real-time processor, and six interactive display areas. The TIPS facilitates rapid reconfiguration to meet changing operational needs or to continue operation in the face of equipment failures. The cost and lead time required for support of new requirements and also operation and maintenance costs will be substantially reduced. TIPS is the first Air Force data system processed under the Design-to-Cost/Life Cycle Cost (DTC/LCC) philosophy; all design and specification changes are evaluated in terms of operational as well as initial costs. Notable achievements in the TIPS implementation are the Telemetry Compiler and the real-time acquisition and processing subsystems which are described in accompanying papers.
    • TIPS Real Time Acquisition, Processing and Display Subsystem

      Straehley, Erwin H.; Straehley Associates (International Foundation for Telemetering, 1978-11)
      The requirement to acquire, process, and display telemetry data from increasingly sophisticated test vehicles in real time is one of the, principal parameters that shaped the SAMTEC Telemetry Integrated Processing System (TIPS) design. An integrated subsystem incorporating advances in hardware design, linked by a multi-processor software element implementing three distinct processing functions to fill this requirement, is described in this paper. Most of the hardware elements, except the processor, were designed to meet the specific requirements of this system. This includes telemetry front-end acquisition equipment, electrostatic high speed printer plotters, plasma keyboard displays, and wide band links to transfer data from element to element. The processors are 32-bit word third generation midi-computers. Each element was selected or specified primarily for its ability to perform at the expected incoming data rates. The Real Time Acquisition (RTA) Software is partitioned into an executive function, an acquisition and event processing function, and a display processing function. Each function resides in its own specific computer configuration. The acquisition configuration (TPP) and display configuration (QLDA) are each replicated to provide multi-input stream and multiple independent display capabilities. Real time requirements, similar to those at SAMTEC, are evolving elsewhere. The hardware and software components described herein are easily adaptable to satisfy these requirements at a variety of other advanced telemetry data processing facilities.
    • TIPS Telemetry Compiler

      Billerbeck, G.; Idsardi, R.; System Development Corporation (International Foundation for Telemetering, 1978-11)
      The TIPS Telemetry Compiler is a keyworded-free format language processor used to generate run-time tables for controlling the real-time software and front-end hardware of the Telemetry Integrated Processing System (TIPS) at Vandenberg Air Force Base. The use of a compiler shortens response time to new requirements and improves analyst productivity. The Telemetry Source Language (TSL) is the interface between the telemetry analyst and the compiler. For example, TSL statements are used to specify parameters for the telemetry stream, compression algorithms, data acquisition, display, and history recording. Considerable flexibility has been built into the internal structure of the compiler by the use of an Input Control Definition Language (ICDL) to define the construction of the TSL. The flexibility provided by the use of an ICDL to map the source language into the compiler data base is essential for adapting the compiler to requirements beyond the scope of the original construction. The compiler data base is sufficiently large and complex to require the implementation of data base management and memory management techniques. The nature of these facilities is important for a modular architecture and for reasonable computational efficiency. These key features of the internal structure of the Telemetry Compiler are transparent to the Compiler user. The output of the compiler is a Run-Time File for use by the Real-Time Software in loading the programmable front-end hardware and in software process control. The TIPS Telemetry Compiler is written in structured FORTRAN on a CDC CYBER 173. The real-time software executes on a network of SEL 32/55 processors. At the time of publication, the framework of the compiler was completed as well as major portions of the run-time file generation phase, and the compiler had been used to build run-time files for major development milestones.
    • A Transition Density Analyzer for High Density Digital Codes

      Petit, R. D.; Odetics Incorporated (International Foundation for Telemetering, 1978-11)
      A portable test instrument useful in optimizing the performance of high density digital recorders is described in this paper. The instrument, a transition density analyzer, provides a graphic display of the distribution of transitions with respect to time for a variety of PCM digital data formats. The concept of a transition density analyzer as an improvement upon eye pattern assessment techniques was presented at the 1976 International Telemetering Conference by Mr. J. P. Lerma of Odetics, Inc., Anaheim, California. Mr. Lerma's paper emphasized the mathematical modeling of probability density functions and the synthesis of these models by a density analyzer. Mr. Lerma's concept has since been reduced to a working prototype which is currently under evaluation at Odetics. Discussed in this paper are the operational characteristics of the instrument as well as applications and the results of its usage on some high density digital recorders.
    • The USAF Fault Tolerant Spaceborne Computer

      Schmiesing, Roy L.; USAF Space and Missile Systems Organization (International Foundation for Telemetering, 1978-11)
      A Fault Tolerant Spaceborne Computer is being developed for long duration military space missions. The user requirements, the architecture, the computational characteristics, the LSI microcircuit technology selected and the program's present status are described.
    • Video Encoding for the Space Shuttle

      Habibi, A.; Batson, B. H.; TRW Defense and Space Systems Group; NASA Lyndon B. Johnson Space Center (International Foundation for Telemetering, 1978-11)
      The Space Shuttle will initially be using a field sequential color television system but it is possible that an NTSC color TV system may be used for future missions. In addition to downlink color TV transmission via analog FM links, the Shuttle will use a high resolution slow-scan monochrome system for uplink transmission of text and graphics information. This paper discusses the characteristics of the Shuttle video systems, and evaluates digitization and/or bandwidth compression techniques for the various links. The more attrative techniques for the downlink video are based on a two-dimensional DPCM encoder that utilizes temporal and spectral as well as the spatial correlation of the color TV imagery. An appropriate technique for distortion-free coding of the uplink system utilizes two-dimensional HCK codes.
    • VLSI Memories Problems and Promise from a Military Viewpoint

      Vail, Patrick J.; Hanscom AFB (International Foundation for Telemetering, 1978-11)
      Many of the problems that military magnetic and mechanical memories experience can be overcome by using Very-Large-Scale-Integrated (VLSI) circuits. These VLSI memories can present problems of their own, however. This paper outlines an assessment of the state-of-the-art in military memories that was performed to identify VLSI memory technology gaps that need additional development effort.
    • Wafer Integrated Semiconductor Mass Memory

      Geiderman, William A.; Solomon, Allen L.; McDonnell Douglas Corporation (International Foundation for Telemetering, 1978-11)
      This paper describes a light-weight, small-volume, low-power semiconductor mass memory which will provide high reliability operation in a variety of environments. The memory employs two new technologies: adaptive wafer scale integration where large numbers of memory arrays are interconnected on the wafer substrate using nonvolatile latching circuits; and a nonvolatile charge-coupled device memory element. The nonvolatile charge-coupled devices and peripheral circuitry are fabricated on a single silicon substrate using metal-nitride-oxide-semiconductor (MNOS) transistor structures. The adaptive latching circuits enable malfunctioning arrays to be replaced in situ by spare arrays which are available on the wafer substrate through the use of error detection/ correction circuitry. The paper also describes a specification for a spaceborne mass memory system including peripheral circuits. A memory system with a gigabit data storage capacity (total active storage elements = 1.2 gigabits can be fabricated within 0.6 cubic feet at an estimated weight of 26 pounds.
    • The Wide-Band Signal Processor

      Stiffler, J. J.; Raytheon Company (International Foundation for Telemetering, 1978-11)
      The Wide-Band Signal Processor (WBSP) is a spaceborne communications processor designed to operate as a peripheral to the Fault-Tolerant Spaceborne Computer (FTSC) currently being developed for the U. S. Air Force. Its function is to demodulate and decode received FDM and TDM signals and to re-encode the recovered information and use it to modulate signals for retransmission. The major difference between the WBSP and other processors designed to perform similar functions is in the fact that the WBSP, like the FTSC itself, is designed to survive its own hardware malfunctions.