• A DIGITAL DEVICE FOR FAST ACQUISITION OF PSEUDO-RANDOM CODE

      Gu, X.M.; Wang, J.P.; Yuan, S.J.; Li, W.S.; Zhang, Y.J. (International Foundation for Telemetering, 1991-11)
      A digital device for rapid acquisition of the initial phase of PN code has been implemented. The principles and results of the experiment are introduced in this paper. The m PN code is modulated on IF with BPSK type. The cycle of PN code P=255 chips. The rate of PN code R=5.1 × 10 chips /s. The IF is not acquired. The shift in Doppler 6 frequency f is within l-4KHz. In these conditions, the phase of PN code can be acquired d within 3 ms and the error of sychronization is less than 0.5 chip.
    • THE ROLE OF THE PC IN GROUND TELEMETRY DATA ANALYSIS

      Burkhart, Fred; Chang, Chia-Mu; Loral Instrumentation (International Foundation for Telemetering, 1991-11)
      The growth of personal computer use was explosive in the last decade. In the telemetry industry, however, the adaptation and utilization of a PC-based telemetry instrument for high-speed data processing and display did not come about until the Intel 80386™ or equivalent processors were widely used in the late 1980s. At this time, the power of these processors finally began to meet the requirement to display, store, and play back the high-speed data (such as 10 Mbps with an embedded asynchronous data stream) that is typical in telemetry applications. Many users are still hesitant to use PCS for their telemetry applications because of the real-time limitations of these instruments. This paper will examine the advantages and disadvantages of PC-based test equipment, the performance these instruments, and the future of PC-based telemetry instrumentation. This paper will also focus on Loral Instrumentation’s d*STAR as an example of a PC-based telemetry system.
    • FARADAY CUP SYSTEM CONTROL LOGIC ON THE WIND SPACECRAFT

      Mavretic, Anton; Konstantinidis, Anastasios; Gergin, Emile; Zhou, Runde; Boston University (International Foundation for Telemetering, 1991-11)
      A satellite-mounted instrument has been developed to measure the energy spectrum of the solar proton flux in the solar wind. The instrument consists of a sensor --- the Faraday Cup, an analog signal processing chain, a high voltage modulator and a digital section. This paper presents the digital section designed and built in our laboratory which functions well to (a) interface with the main processor, (b) to provide the logic signals with proper timing to the analog circuitry, (c) to deliver the necessary bit pattern to the high voltage modulator, (d) to provide the calibration mode control signals when necessary, and (e) to synchronize the sequence of events at the begining of every spacecraft rotation. As with all space projects primary concerns beyond the logical functionality consistes of circuit power consumption, instrumental mass, radiation tolerance levels, stability with respect to temperature, and relative ease of component procurement. The NASA WIND laboratory spacecraft that will carry the experiment is due to be launched in December of 1992 and eventually come to park in an orbit at the first Lagrangian point.
    • THE BRIDGE FUNCTION TELEMETRY SYSTEM

      Qishan, Zhang; BEIJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS (International Foundation for Telemetering, 1991-11)
      Based on the theory of orthogonality, two orthogonal multiplex systems called frequency division multiplexing (FDM) and time division multiplexing (TDM) have long been developed. Therefore, many people tend to think that these two systems represent the ONLY two multiplexing methods that satisfy the orthogonal condition. However, after years of research, we've discovered a new kind of orthogonal functions called Bridge functions. The Bridge functions have the every promise of being the basis for constructing an entirely new kind of telemetry system, which has been named as sequency division multiplexing (SDM). Since the Bridge functions are the mathematical basis of the new telemetry system, we will give a summary of the Bridge functions at first. We have successfully constructed an experimental prototype called BAM-FM system in our laboratory. The main ideas, block diagram, operational principles, and technical problems are discussed in this paper. All our work has proved that SDM has not only research interests, but also practical value.
    • RAPID PROTOTYPING AS AN ACQUISITION STRATEGY OF THE AIR FORCE SATELLITE CONTROL NETWORK

      Whipple, L.K.; Hoida, T.J.; USAF Space Systems Division (International Foundation for Telemetering, 1991-11)
      The Air Force Satellite Control Network (AFSCN) processes on the order of a thousand separate requirements each year to enhance Network capability to meet the support needs of various satellites. Many of these individual requirements are translated into modifications or additions to the network assets. Rapid Prototyping has been utilized successfully for complex and urgent developments to meet many of these requirements. Rapid Prototyping has also been used for requirements definition and for defining man/machine interfaces. Through Rapid Prototyping, the AFSCN has successfully developed applications using new technology and has improved the process of defining requirements for operational satellite support systems. Rapid prototyping is proving to be an effective alternative to the traditional system acquisition process
    • THE EVOLUTION OF AFSCN TELEMETRY SIMULATION SYSTEMS

      Dessling, R.W.; Lockheed Technical Operations Company (International Foundation for Telemetering, 1991-11)
      The Air Force satellite control capability was started in the late 1950s to support command and control of orbiting spacecraft. A need to train and certify ground support personnel as well as to validate equipment configurations soon became evident. Ground personnel would have to know how to generate satellite contact plans, establish connectivity between the satellite and telemetry display terminals, analyze satellite telemetry data, and transmit commands to execute the contact plans. They would have to learn specific ground systems capabilities, satellite design information, and approved command and control procedures. This presentation will review the evolution of telemetry simulation systems as they apply to systems test, personnel training and evaluation. Included will be a discussion of the ground and satellite systems, and how system upgrades and changing operations concepts have fostered the development of telemetry simulators. In describing the next generation of AFSCN simulation systems, this paper will highlight the important part they play in validating system configuration and in personnel training.
    • A DSP IMPLEMENTED DIGITAL FM MULTIPLEXING SYSTEM

      Rosenthal, Glenn K.; Metraplex Corporation (International Foundation for Telemetering, 1991-11)
      Recent advancements in high-speed Digital Signal Processing (DSP) concepts and devices permit digital hardware implementation of relatively high-frequency signal processing, which formerly required analog circuitry. Systems utilizing this technology can provide a high degree of software programmability; improved reproducibility, reliability, and maintainability; immunity to temperature induced drift errors; and compare favorably in cost to their analog counterparts. This paper describes the DSP implementation of a software programmable, digital frequency multiplexed FM system providing up to 4 output multiplexes, containing up to 36 subcarrier channels extending up to 4 MHZ, and accommodating modulating frequencies up to 64 kHz. System overall design goals and the implementation of these goals are presented.
    • International Telemetering Conference Proceedings, Volume 27 (1991)

      International Foundation for Telemetering, 1991-11
    • APPLICATIONS AND DESCRIPTION OF THE 9000SE PCM SIMULATOR FOR SIMULATION OF PCM DATA

      Conell, David; Terametrix Systems International (International Foundation for Telemetering, 1991-11)
      This paper will discuss the needs and requirements of a PCM encoder data simulator. The 9000SE PCM encoder data simulator allows for the simulation of flight PCM data as well as bit error rate (BER) test patterns designed for link stress analysis. In addition, the open architecture of the 9000SE as an ISA bus device allows for the incorporation of the simulator into application specific realtime systems.
    • USING DATAFLOW ARCHITECTURE TO SOLVE THE TRANSPORT LAG PROBLEM WHEN INTERFACING WITH AN ENGINEERING MODEL FLIGHT COMPUTER IN A TELEMETRY SIMULATION

      White, Joey; CAE-Link Corporation (International Foundation for Telemetering, 1991-11)
      One of the most challenging technical problems in the development of a spacecraft telemetry simulation is the interface with a flight computer running real-world flight software. The ability of the simulation to satisfy flight software requests for telemetry data, and to load, mode, and control the flight software along with the simulation, can be constrained or degraded using conventional interface solutions. Telemetry dataflow architecture systems can be utilized to solve the interface problems with less constraints. This is an especially attractive solution in a telemetry simulation where the telemetry system can also be used to format and serialize spacecraft telemetry, and receive and preprocess commands. This paper discusses the concepts developed for such a system for a training simulation of the Orbital Maneuvering Vehicle for NASA at Johnson Space Center.
    • MODERNIZING THE REMOTE TRACKING STATION

      Blanchard, W. N. (International Foundation for Telemetering, 1991-11)
      Since the inception of the Air Force Satellite Control Network (AFSCN) in the late 1950s, capabilities of the network’s Remote Tracking Stations (RTSs) were evolutionarily developed to meet satellite Tracking, Telemetry, and Commanding (TT&C) needs. The result, although fully satisfactory operationally, was an RTS network requiring manpowerintensive mission support. Additionally, reconfiguration of an RTS between satellite contacts consumed far more time than was operationally desirable as demands for RTS contact support continued to grow. To improve network responsiveness and cost effectiveness, the Air Force undertook, in the mid-1980s, a major “block upgrade” under the Automated Remote Tracking Station (ARTS) Program. This paper traces historical RTS capabilities, identifies emerging mid1980s RTS support requirements, and defines the operational and financial advantages accruing to the Air Force through ARTS implementation to meet those requirements. Possible future upgrades to further enhance AFSCN TT&C mission capability are also briefly discussed.
    • A GENERIC OBJECT-ORIENTED DESIGN FOR A RADIO FREQUENCY SIMULATION IN A SPACE TELEMETRY AND COMMAND ENVIRONMENT

      Policella, Joseph; CAE-Link Corporation (International Foundation for Telemetering, 1991-11)
      In a generic telemetry simulation the overall fidelity of the simulation is largely based on the simulated vehicle’s On-Board-Systems (OBS) engineering models that drive the generation of the telemetry. Also, the actual transfer of data between the simulated vehicle and control center depends on the ability of the Radio Frequency (RF) OBS to acquire and process the RF links thus resulting in a Acquisition of Signal or Loss of Signal (AOS/LOS) determination. The simulated RF links are a function of the communications OBS models, and the communications environment models. The communications OBS models are responsible for propagating the RF signal. Since the RF link analysis is highly integrated into the characteristics of the communications equipment and environment models, RF link software needs to be constantly redeveloped as communications equipment models change, fidelity is added, or multiple links are created. However, by using a generic objectoriented design, RF link software can process any number of differing links based on the RF characteristics of the propagated wave. As a result, the communications equipment model software can be changed to reflect possible design changes without having to rewrite the RF link software thus allowing reuse of existing code.
    • EXPERT ANALYSIS OF TELEMETRY DATA

      Delatizky, Jonathan; Morrill, Jeff; Lynch, Thomas J., III; Haberl, Karl; Bolt Beranek and Newman Inc. (International Foundation for Telemetering, 1991-11)
      We describe FAES, a knowledge-based system for postprocess interpretion of telemetry data obtained from in-water tests of the Torpedo MK48 ADCAP and recorded on tape in a telemetry format. The system is designed to automate a diagnostic application in fleet operations. A generic software solution provides the infrastructure for customization through application-specific knowledge representation. Pattern recognition provides a feature-extraction layer between the raw data and an expert system, and gives domain experts a natural and comfortable representation. Use of features abstracted from the raw data greatly reduces the complexity of encoding the rules that describe the behavior of the system under investigation. This allows the experts – not the system programmers – to control the resulting software. The approach has led to development of a system which accurately determines the cause of shutdown in torpedo tests and which will be extended to the full range of diagnostics now done manually. A slightly modified system is being used to support torpedo proofing by automating comparisons of recorded data with the weapon specification and alerting engineers to violations.
    • A GUI BASED SYSTEM FOR AUTOMATIC CONSTRUCTION OF ENGINEERING MODEL SOFTWARE FOR COMMAND RESPONSE AND TELEMETRY GENERATION

      Parlanti, Joe; Pinkerton, Ronnie; CAE-Link Corporation (International Foundation for Telemetering, 1991-11)
      There exists today, numerous off-the-shelf hardware solutions for the generation of simulated telemetry data streams. The ability to rapidly develop engineering models to drive the data contents of the telemetry is restricted by the lack of contemporary CASE tools. This paper presents an object-oriented Graphical User Interface (GUI) approach to generation of mathematical models in order to reduce the time required for model generation to a fraction of today’s development time, eliminate the need to write substantial amounts of software, and allow reuse of model objects in a manner consistent with the GUI cut, paste, and copy metaphors.
    • A Real-time Counting-measuring Method for PPM(PPK) Signals

      Xi-Hua, Li; Xinan Electronic Engineering Institute, China (International Foundation for Telemetering, 1991-11)
      On the disscussion of custom real-time counting-measuring method, this paper presents a new method suitable for the working condition of non-man duty, which possesses the feature of 100ns counting-measuring accuracy and high fidelity. In addition, the concept of “Signal-time/digit converter” is proposed for the first time and the principle and working procedure of this method are introduced in brief.
    • PCM BIT SYNCHRONIZATION TO AN Eb/No THRESHOLD OF -20 dB

      Schroeder, Gene F. (International Foundation for Telemetering, 1991-11)
      This paper presents an overview of a digital PCM adaptive bit synchronizer capable of bit synchronization down to an Eb/No of -20 dB where Eb/No is the energy contrast ratio. The topics addressed include: 1. Functional block diagrams. 2. Loop bandwidth as a function of synchronization threshold. 3. Accuracy, resolution and stability requirements of the Numerically Controlled Oscillator (NCO) and Loop Filter (LF). 4. Performance data. The purpose of this paper is to highlight the major components of a unit capable of performing this task based on an actual development program.
    • MISSILE FLIGHT SAFETY AND TELEMETRY AT WHITE SANDS MISSILE RANGE

      NEWTON, HENRY L.; WHITE SANDS MISSILE RANGE, NM (International Foundation for Telemetering, 1991-11)
      Missile Flight Test Safety Managers (MFTSM) and other flight safety personnel at White Sands Missile Range (WSMR) constantly monitor the realtime space position of missile and airborne target vehicles and the telemetered missile and target vehicle performance parameters during the test flight to determine if these are about to leave Range boundaries or if erratic vehicle performance might endanger Range personnel, Range support assets or the nearby civilian population. WSMR flight safety personnel rely on the vehicle telemetry system to observe the Flight Termination System (FTS) parameters. A realtime closed loop that involves the ground command-destruct transmitter, the vehicle command-destruct receiver (CDR), other FTS components, the missile S-band telemetry transmitter, and the ground telemetry acquisition/ demultiplex system is active when the vehicle is in flight. The FTS engineer relies upon telemetry to provide read-back status of the flight termination system aboard the vehicle. WSMR flight safety personnel use the telemetry system to assess realtime airborne vehicle systems performance and advise the MFTSM. The MFTSM uses this information, in conjunction with space position information provided by an Interactive Graphics Display System (IGDS), to make realtime destruct decisions about missiles and targets in flight. This paper will aid the missile or target developer in understanding the type of vehicle performance data and FTS parameters WSMR flight safety personnel are concerned with, in realtime missile test operations.
    • GULF RANGE DRONE CONTROL UPGRADE SYSTEM MOBILE CONTROL SYSTEM

      Wagner, Steven M.; Goodson, John H.; General Electric Government Services, Inc.; Eglin Air Force Base, Florida (International Foundation for Telemetering, 1991-11)
      The Gulf Range Drone Control Upgrade System (GRDCUS) Mobile Control System (GMCS) is an integral part of the test ranges located on the Gulf of Mexico. This paper begins with a brief overview of the current Gulf Range systems. These systems consist of five major components: ground stations, ground computer systems, data link/transponders, consoles, and software. The GMCS van contains many of these components to provide a stand-alone range capability for remote operations. This paper describes the development and assembly of the GMCS van and focuses on the on-board computer systems, consoles, and data link technology. An overall system engineering approach was used during GMCS development and is highlighted through the use of rapid prototyping. This methodology and the lessons learned are presented in the paper. Suggestions for future applications are considered.
    • IMAGE DATA COMPRESSION (USING DPCM)

      Karki, Maya; Shivashankar, H.N.; Rajangam, R.K.; Dept. of Electrical Engg., U.V.C.E., Bangalore; DSD-ISRO, Bangalore (International Foundation for Telemetering, 1991-11)
      Advances in computer technology and mass storage have paved the way for implementing advanced data compression techniques to improve the efficiency of transmission and storage of images. The present paper deals on the development of a data compression algorithm suitable for images received from satellites. The compression ratio of 1.91:1 is achieved with the proposed technique. The technique used is 1-D DPCM Coding. Hardware-relevant to coder has also been proposed.
    • ARCHITECTURE FOR A NEXT GENERATION TELEMETRY AND DATA ACQUISITION BUS

      DAWSON, D.M.; VEDA SYSTEMS INCORPORATED (International Foundation for Telemetering, 1991-11)
      During the requirements definition process for a new telemetry and data acquisition product, Veda Systems engineers had the opportunity to examine the requirements for the ideal bus architecture to support future needs. Design goals and requirements were solicited from major users in flight test, space ground station data monitoring and command applications, and C41, as well as Veda’s own engineers. The process resulted in a bus architecture design which could potentially set the standard for the next generation of telemetry and data acquisition systems. This paper outlines the design goals selected and the thought process that yielded the goals in an attempt to promote advancement of current bus design approaches and increased availability of standard architectures and operating environments.