Bokulic, Robert S.; The Johns Hopkins University (International Foundation for Telemetering, 1986-10)
      The noise performance of the sawtooth phase detector when demodulating a sinusoidal subcarrier plus direct data modulation is studied. At predetection signal-to-noise ratio (SNR) levels of about 10 dB or more, significant improvements in the postdetection SNR of the subcarrier can be obtained using the sawtooth detector rather than a linear multiplier. Below predetection SNR levels of about 10 dB, significant improvements can still be obtained; however, a threshold occurs and the performance degrades until leveling off at 3.2 dB worse than that of a linear multiplier. The predetection SNR level where the sawtooth detector performance becomes worse than that of a linear multiplier depends upon the subcarrier and direct data modulation indices. Performance curves are given between predetection SNR levels of -20 dB and +20 dB for various values of subcarrier modulation index and direct data modulation index.

      Richards, William F.; University of Houston, University Park (International Foundation for Telemetering, 1986-10)
      A study has been undertaken to determine the feasability of dynamically controlling the input impedance of a microstrip antenna element by changing its reactive loading. The major applications of such an element would be for use in a scanned phased array. By changing the loading of individual elements appropriately, one could alter the active array impedance of the elements to compensate to some degree for the onset of scan blindness. While the ultimate feasability of such applications cannot yet be firmly established, a single element can be controlled using PIN diodes to effectively alter its input impedance. The generalized theory of loaded microstrip antennas has been used to predict the impedance of a variety of microstrip, antenna configurations with multiple loads. This work has shown the possibilities of changing the input impedance of the radiator over a wide range of values without affecting its resonant frequency or radiation pattern by moving a set of short-circuited loads from one position to another. Actual printed-circuit antennas were fabricated based on this design and good correlation was found between theory and experiment.

      Kurisu, Kurtis Lee; Aerospace Corporation (International Foundation for Telemetering, 1986-10)
      The Space-Ground-Link-Subsystem (SGLS) has been providing Telemetry, Tracking, and Commanding (TT&C) services to the Air Force Satellite Control Facility (SCF) since the late 1960’s. The current transmitter system is comprised of a 10 kW travelling wave tube (TWT) and associated equipment. As solid state technology matures, it is now appropriate to consider alternative approaches. Solid state offers the potential advantages of improved reliability, graceful degradation, high efficiency, and lower life cycle costs. This paper addresses the current status of solid state multi-kilowatt systems development. The present state of solid state power transistors and low loss power combiners are at a stage where high power S-band CW transmitters are possible. The advantages and disadvantages of the state of the technology are discussed as are the practical considerations for integration into SGLS systems applications.

      BALCH, KRIS S.; Eastman Kodak (International Foundation for Telemetering, 1986-10)
      Today I will describe the application of the Autocorrelation function to the Magnetic Recording Channel. I will explain what is an autocorrelated function, how does it behave and where may it be applied in the Magnetic Recording channel. There will be a brief description of Kodak San Diego’s Autocorrelator and how we apply this technology. If I have done my job well at the end of this presentation you will have enough knowledge about autocorrelation to access your own application. Before I start, let me give a brief overview on the application of an Autocorrelator. The Autocorrelator can be used to collect information on signals in a magnetic recording system and display this information graphically as a statistical plot. Autocorrelation, in the time domain, is the counter part to a spectrum analyzer in the frequency domain (Fourier Pair). The information about the signal of interest must be stored for post analysis. This information called a database must then be processed by a computer. The computer passes the database through the autocorrelation algorithm and produces a second database. This second database represents a plot of the autocorrelated function. The next step is to plot the database on a video screen. This plot can be examined for periodicities, randomness, and relational influences on a captured signal. In our application, this signal is an error flag or a dropout flag. We want a statistical picture of the magnitude of errors and their relative frequency. The information gained from Autocorrelation can aid in solutions for: Error Correction Codes Media Evaluation/Qualifications Media Process Defect Identification Mechanical Eccentricities Modulation Code Performances System’s Figure of Merit To use a cliche, “one picture is worth a thousand words,” is exactly the point of the Autocorrelator’s graphical display. It yields information useful to those disciplines which often find difficulty in describing an event in understandable terms.
    • Data Synthesis in PCM Telemetry System

      Futang, Zhang; Xinan Electronic Engineering Institute, China (International Foundation for Telemetering, 1986-10)
      In the field of re-entry telemetry, data synthesis is an important research task for multibeam and multi-reseiver system. This paper presents a microcmputer-based method to synthesize PCM data in real-time. The performances of various criteria used in data synthesis systems are also analyzed here.

      Trover, William F.; Teledyne Controls (International Foundation for Telemetering, 1986-10)
      A realtime, multi-system, dynamic vehicle test capability has been developed for the testing of tanks and large vehicles under all possible conditions of terrain and environment. The systems, produced under a turnkey contract, include: a fixed base ground data processing system; a mobile ground station with the same processing capability; two vehicle-borne systems with on-board computing, recording and telemetry; and a large integrated software package for all four systems. The mobile ground station can be mounted on a rail car, a ship or the chassis of a diesel truck capable of operating across open field terrain. All four systems have computers and realtime EU data displays. The vehicle-borne systems can be assembled and mounted inside a tank turret for underwater testing. Optionally, they can be installed in an environmental enclosure mounted to the outside of the vehicle for open field testing or tests where the armament supply hardware must be installed inside the armored vehicle. Several special sensors were developed for the vehicle-borne instrumentation to permit measurement and display of terrain contour, ground speed, track efficiency, power train performance, vehicle direction, velocity and acceleration in 3-axes, vehicle attitude and stability, dynamic gun pointing accuracy, engine and transmission performance and operator reaction to the test requirements and the vehicle environment.

      Beffa, James C.; Ishii, T. Koryu; Marquette University (International Foundation for Telemetering, 1986-10)
      A millimeter wave radio responder was evaluated as a remote sensor of surface conductivity and laser light intensity. A 10 mm CdSe photocell was illuminated by a 1/4 mW, 632.8 nm He-Ne laser light. The photocell was not connected to anywhere. The terminals were left open. The photocell was interrogated by a remotely placed millimeter wave radio responder operated with the frequency of 69.6 GHz and the transmitter power of 3 mW. The millimeter wave radio responder was able to sense the radio echo from the surface of the photocell. The laser illuminated area on the photocell was only 2.86% of the entire active area, yet the radio responder output showed up to 15 dB difference between the laser spot on and off from the target. The minimum reflected signal change observed was 0.002 dB by tilting the target 20 degrees from the normal incidence of the millimeterwave beam. This was translated to be 0.025% of surface conductance change on the target. This remote sensing was done using an instrumentation of the sensitivity of !40 dBm. Thus, the usefulness and advantage of employing a millimeter wave radio responder for remote sensing of minute change in the surface conductivity and/or the laser light intensity have been demonstrated in this research.

      Russell, William P.; Naval Air Test Center (International Foundation for Telemetering, 1986-10)
      An integrated 1553 Data Bus Monitor (DBM) System has been developed at the Naval Air Test Center. The system is capable of monitoring six 1553A or B channels and provides, in separate PCM streams, selected parameter data and all message traffic on the data bus (thruput). Thruput data can be split to two tape tracks per channel for bandwidth conservation. Selected parameter formats can be entered at the flight line with a hand-held programmer which communicates to the DBM via an RS-232 interface. PCM outputs are available for telemetry as well as for on-board recording. Analog and discrete data is incorporated in the system with A/D inputs, parallel inputs, or serial entry of PCM data from a remote PCM system. A 1553 remote terminal provides data to the F-18 mission computer. Existing systems are being used on AMRAAM Development in the F-18 and in follow-on F-18 development at the Naval Air Test Center.

      RAJYALAKSHMI, P.S.; RAJANGAM, R.K.; ISRO SATELLITE CENTRE (International Foundation for Telemetering, 1986-10)
      In most transmission channels, bandwidth is at a premium and an important attribute of any good digital signalling scheme is to optimally utilise the bandwidth for transmitting the information. The Data Compression System in this way plays a significant role in the transmission of picture data from any Remote Sensing Satellite by exploiting the statistical properties of the imagery. The data rate required for transmission to ground can be reduced by using suitable compression technique. A data compression algorithm has been developed for processing the images of Indian Remote Sensing Satellite. Sample LANDSAT imagery and also a reference photo are used for evaluating the performance of the system. The reconstructed images are obtained after compression for 1.5 bits per pixel and 2 bits per pixel as against the original of 7 bits per pixel. The technique used is uni-dimensional Hadamard Transform Technique. The Histograms are computed for various pictures which are used as samples. This paper describes the development of such a hardware and software system and also indicates how hardware can be adopted for a two dimensional Hadamard Transform Technique.

      FINN, GERALD T.; THE AEROSPACE CORPORATION (International Foundation for Telemetering, 1986-10)
      The Air Force Satellite Control Network (AFSCN) provides real-time telemetry, tracking and command (TT&C) services for the Department of Defense (DoD) space systems. It consists of a worldwide network of Remote Tracking Stations (RTSs), the Air Force Satellite Test Center (STC), at Sunnyvale, California, and the soon to be completed Consolidated Space Operations Center (CSOC), located near Colorado Springs, Colorado. The object of this paper is to present an overview of the wideband communications systems which provide connectivity between these elements, and the planned evolution of the communications architecture required to support future growth.

      Plecity, Mark S.; ARIA Programs Division, Wright-Patterson Air Force Base, Ohio (International Foundation for Telemetering, 1986-10)
      The Advanced Range Instrumentation Aircraft (ARIA) is an airborne platform to receive, record, process and retransmit telemetry data. This paper presents a summary of ARIA’s capabilities with emphasis on airborne testing of the Advanced Medium Range Air to Air Missile (AMRAAM) program. The unique test scenarios, as well as current and future telemetry requirements of the AMRAAM test program are discussed.

      DAHAN, MICHAEL; LOD ISRAEL (International Foundation for Telemetering, 1986-10)
      This paper describes an on-board PCM data acquisition and processing system using standard PCM units and commercial micro-computer equipments. A special interface, which was developed in order to allow a direct connection to PCM encoders, is also presented. It performs data buffering and decommutation prior to the data acquisition process. This approach facilitated the independent conduction of flight tests away from the users’ ground stations using a minimal investment. It helped to provide test results in flight or immediately after flights, thus shortening the flight test processing turn around time and contributing to expedite the overall flight test program.

      McConnell, John B.; Hoefener, Carl E.; Western Space and Missile Center; Interstate Electronics Corporation (International Foundation for Telemetering, 1986-10)
      The NAVSTAR Global Positioning System (GPS) allows extremely accurate global determination of time as well as position and velocity. Currently, the DoD test and training ranges of the United States are working towards using GPS to obtain position and velocity information and recently attention has been given to using GPS for precise range timing. This paper provides background information, discusses the advantages of using GPS for range timing, and describes two timing system configurations using Tri-Service GPS range equipment.

      Skinner, Patrick J.; Ford Aerospace & Communications Corporation (International Foundation for Telemetering, 1986-10)
      Modernizing labor intensive Remote Tracking Stations (RTS), increasing individual station capacity, and providing interoperable links between three separate Air Force satellite networks are the objectives of the Automated RTS (ARTS) program now half way to completion.

      Anderson, William D.; Naval Air Test Center (International Foundation for Telemetering, 1986-10)
      The Naval Air Test Center, Range Directorate, has developed a Telemetry Relay Airborne Command System (TRACS) utilizing a Convair UC-880 aircraft. In its present configuration, the UC-880 can receive, record, and display telemetry data in real time; reshape and retransmit the telemetry data; act as a command center for TOMAHAWK cruise missile operations; provide radar range surveillance; remotely control instruments, cameras, emitters, and electronic countermeasures equipment on target hulks; provide inflight refueling of aircraft; process and display on CRT’s the maps of the area of operations and the missile profiles and tracks on the maps; and provide over-the-horizon target displays using a satellite communication system. This paper will present the development of the UC-880 TRACTS and the results of operations that utilized this system. The system characteristics, design constraints, and future plans will be discussed.

      McCulloch, John D.; Federal Electric Corporation (International Foundation for Telemetering, 1986-10)
      The Telemetry Integrated Processing System (TIPS) at the U.S. Air Force Western Space and Missile Center (WSMC), Vandenberg AFB, California, is a large scale, computer based, telemetry decommutation and data processing system. This system is utilized to process telemetry data from numerous missile and aircraft programs supported at the WSMC. In the late 1970’s and early 1980’s, while TIPS was under development, some information on this unique system was presented at the ITC. This paper will present an overview of the operational system as it exists today. Hardware and software components will be discussed. A presentation of the standard, no development cost, features available to Range users will be made. A summary of the current missile/aircraft telemetry systems that must be supported will be included along with some of the special processing developed for these systems. The primary emphasis will be an overview of the system capabilities and the types of telemetry processing encountered in the operational WSMC environment.

      CONN, RAYMOND; BREEDLOVE, PHILLIP; LORAL DATA SYSTEMS (International Foundation for Telemetering, 1986-10)
      The modern Pulse Code Modulation (PCM) telemetry system faces many unique challenges in terms of data acquisition diversity and specifically satisfy the demanding missile requirements. The engineering considerations and hardware implementation are presented in this paper.

      Smith, Kevin; Windingland, Kim L.; General Dynamics Convair Division; Loral Instrumentation (International Foundation for Telemetering, 1986-10)
      Due to the increasing complexity of systems on which telemetry is used, the method of embedding a data stream within the main PCM data stream is becoming a popular means of acquiring subsystem data. However, this technique increases the complexity of the decommutating requirement in that the embedded stream must first be extracted from the main stream and then decommutated. One obvious solution would be to re-serialize the extracted data stream to be decommutated by a second set of frame and subframe synchronizers. This method suffers from increased system cost due to the additional hardware needed solely to support the embedded data stream. This paper will address an alternate method developed by Loral Instrumentation and an actual application at General Dynamics, Convair Division. This technique decommutates asynchronous embedded data streams via standard algorithms in a data compressor.

      Tate, James A.; IBM Federal Systems Division (International Foundation for Telemetering, 1986-10)
      A telemetry processing capability is being developed for the Air Force Satellite Control Network which will process telemetry data from Air Force satellites of various families in several Mission Control Complexes using identical hardware and software. A Telemetry Higher Order Language is the key element in allowing this commonality.

      Ham, Christopher V.; New Mexico State University (International Foundation for Telemetering, 1986-10)
      This paper describes a system utilizing off-the-shelf microprocessor hardware to perform complex high-speed telemetry data preprocessing. The microprocessor equipment involves the latest in the Motorola computer series, namely the 68020 line. The author develops the specifications leading to the need of this type of preprocessor which is currently being developed under a contract to the McDonnell Douglas Helicopter Company. The paper fully describes the configuration of the hardware as well as the software available on the system. Detailed benchmarks of complex algorithms and other data manipulations are described. Test results relating parameter capacity and throughput are addressed. System architecture is described with the various trade-off analyses well defined. This system advances the art of preprocessing telemetry parameters requiring such functions as wild pointing, phase alignment concatenation, and derivations, all at rates in the megaword input.