• Telemetry Applications in Wildland Fire Control

      Warren, John R.; Forest Service, USDA (International Foundation for Telemetering, 1975-10)
      Telemetry will be coming into wider use in wildland fire control because it provides the real-time information needed in decision-making. Two applications are described: transmission of airborne infrared imagery of the fire scene, and the relaying of meteorological data from remote stations. Experimental systems using these types of telemetered data are being developed at the USDA Forest Service's Pacific Southwest Forest and Range Experiment Station. Also under development are computerized models using telemetered and other information for predicting fire behavior.
    • Maximum Likelihood Processing of Experimental Retransmitted Four Frequency Omega

      Rupp, Walter E., Jr.; Calise, Clara L.; Dobry, Thomas E.; Department of the Navy (International Foundation for Telemetering, 1975-10)
      The Global Rescue Alarm Net (GRAN) System utilizes the Omega navigation signals and geopsynchronous satellites for a world-wide search and rescue system. A series of tests was conducted by the Naval Air Test Center, Patuxent River, Maryland, during September and October 1974, to demonstrate the position locating potential of four frequency Omega. In these tests four-frequency-Omega data was retransmitted from seven remote sites through Lincoln Experimental Satellite 6 (LES-6) to a ground station in Dallas, Texas, where it was recorded on magnetic tape. This paper will describe the equipment used to receive the Omega signals and retransmit them to the satellite, the satellite linkace and the ground station reception and recording of the phase data. It will also describe the processing of the collected data using a maximum likelihood estimator and the results of the processing. Finally, the paper will present the conclusions and recommendations drawn from these tests for the use of four frequency Omega in a world-wide search and rescue system.
    • Intersatellite (Nd:YAG) Laser Communications; A System For The 1980's

      Barry, J. D.; Wright-Patterson AFB (International Foundation for Telemetering, 1975-10)
      It is now a certainty that laser communication systems will be operating in space within this decade. The development of a laser communications satellite package began this fall and is to be launched in 1979. The system is to operate at 1000 megabits per second. Laser communications technology has proceeded from purely exploratory research just over five years ago to the successful completion and operation this year of an engineering feasibility model of the satellite system. Laboratory tests have verified the system capability at a serial data rate of 1000 megabits per second. Thermal and vibrational tests have been successfully completed to the test levels of the Defense Meteorological Satellite program.
    • Use of Sonobuoys in Ocean Earthquake Studies

      Reichle, Michael; Bradner, Hugh; University of California (International Foundation for Telemetering, 1975-10)
      U.S. Navy anti-submarine-warfare telemetering sonobuoys have recently become an important tool in the study of earthquakes at sea. Earthquake ground motion converts to sub-audio compressional waves in the water and is detected by the sonabuoy hydrophones. The frequency-modulated sonobuoy signals are monitored with commercial VHF receivers on shipboard, aircraft or land, and are recorded on f.m. magnetic tape or strip chart. Subsequent analysis of the seismic signals gives information on location and depth of the earthquake as well as direction of fault motion, stress release and other characteristics of the event. The accuracy of epicenter location is usually limited by the precision of ship navigation but may also be limited by uncertainties in sonobuoy position measured from the ship. Events large enough to be detected on land have been located with better accuracy by sonobuoys than by the land arrays. This paper describes the techniques of using sonobuoys for earthquake research, and gives results of observations of microearthquake swarms in the Gulf of California along the extension of the San Andreas Fault.
    • Evaluation of a Random Access System with Hardware Simulation

      Delmas, G. G.; Centre National d’Etudes Spatiales (International Foundation for Telemetering, 1975-10)
      The purpose of this study is to solve the problem of the determination of the exact capacity and performances of a satellite location and data collection system using random access. Here is described the method we apply in the particular case of the ARGOS system; the TIROS-N and NOAA-A to G satellites will be equiped with the ARGOS on-board experiment and will ensure an operational service from 1978 to 1985 at least. The results we obtained are significantly better than the first estimations and should allow us to increase the number of the platforms.
    • Multibeam Adaptive Array for RPV Antijam Communication

      Noji, T. T.; Schwartz, L.; AIL (International Foundation for Telemetering, 1975-10)
      An application using a multibeam adaptive array for the simultaneous communications of command control, and telemetry data from 20 Remotely Piloted Vehicles (RPV's) to a command station is investigated. It is assumed that the RPV's are on tactical mission beyond FEBA as typically shown in Figure 1, and that communication links must be established to and from each RPV in the presence of many airborne and/or surface based jammers. The RPV's are assumed to be on data collection missions out to a maximum range of 100 km and must data link the sensor information (including digitized video of 20 Mbps) back to the tactical RPV control center. The data link will be operated at C-band. Other system parameters are summarized in Figure 2.
    • The Geostationary Operational Environmental Satellite/GOES/Imaging Communication System

      Baker, W. L.; Savides, J.; Aeronutronic Ford Corporation (International Foundation for Telemetering, 1975-10)
      The SMS/GOES Satellite obtains day and night weather information from synchronous geostationary orbit by means of (a) earth imaging, (b) collection of environmental data from ground based sensors, platforms, and (c) monitoring of the space environment. SMS-1 and SMS-2 have been in orbit for 17 months and 8 months respectively and are presently taking full earth disc images in the visible and infrared every 30 minutes. SMS-1 is positioned to cover the eastern portion of the United States while SMS-2 is positioned to cover the western portion. This paper provides a general overview of the imaging communication portions of the SMS/GOES, related to the image data encoding and transmission as well as the method of the data time multiplexing and the manner in which the scan line to line synchronization is achieved.
    • Surface Acoustic Wave Devices for Communications

      Webb, D. C.; Naval Research Laboratory (International Foundation for Telemetering, 1975-10)
      Many surface acoustic wave (SAW) devices are now sufficiently well-developed that they can have a significant impact on systems design. This paper reviews the properties and limitations of SAW devices which seem particularly well suited to communications. The simple bandpass filter is considered in detail as it will undoubtedly see the widest usage of all SAW devices. The application of SAW analog matched filters in phase-shift-keyed synchronization and data demodulation is also discussed. Finally, SAW resonators and oscillators are briefly considered. A number of examples are included which show how system performance can be improved through use of SAW technology.
    • Runs of Significant Samples for Processes with Sharp Non-Stationarities: Application to Seismogram Compression

      Babkin, V. F.; Rybeva, N. E.; Shtarkov, Yu. M.; Institute for Space Research (International Foundation for Telemetering, 1975-10)
      An algorithm for threshold compression of the processes with the sharp variations of a level is considered. In broadening the concept on an significant sample we are successful in transmitting completely almost all the samples appropriate to the phenomenon studied; at the same time the compression ratio at the quiet parts is kept at the acceptable level. The experimental results of seismogram compression are given.
    • Use of TSE Computers Aboard Spacecraft

      Schaefer, David A.; NASA-Goddard Space Flight Center (International Foundation for Telemetering, 1975-10)
      The Goddard Space Flight Center has undertaken a program to develop improved methods of handling two-dimensional data. From this, the concept of a new family of computers known as "tse computers," has evolved. These computers utilize entire binary images as their basic computational entity. This is in contrast to conventional computers that utilize a bit as their basic computational entity. Because of their ability to perform thousands of operations simultaneously, they have the potential of operating orders of magnitude faster than conventional computers. They are ideally suited for spacecraft onboard image processing tasks.
    • Low Frequency Telemetry from Terradynamic Vehicles

      Galbraith, L. K.; Sandia Labs. (International Foundation for Telemetering, 1975-10)
      A telemetry system has been designed and built which transmits digital data from a buried earth-penetrating vehicle to the surface by magnetic induction. The transmitting package is a cylinder 10 cm in diameter by 30 cm long and draws 5 watts of dc power while transmitting. Error rates of 1.16 x 10⁻⁴ have been obtained at a range of 52 meters through soil at a data rate of 50 bits/second, utilizing only the 0-50 Hz region of the electromagnetic spectrum. Projected performance of the system in high-conductivity media indicates useful ranges exceeding 50 meters in media as conductive as sea water (4 mho/meter). System improvements are discussed which should allow severalfold increases in data rate or range over the experimentally obtained values.
    • A Telemetry Link for an Earth Penetrator

      Caffey, Thurlow W. H.; Sandia Laboratories (International Foundation for Telemetering, 1975-10)
      The design and field-testing of a telemetry link to send signals to the surface of the earth from an earth penetrator are described. The link uses a PCM/FM format at a frequency of 10.5 kHz, dissipates 8 watts, and fits within a cylinder with an inside diameter of 100 mm. A bit error rate of less than 10⁻⁵ was achieved from a depth of 52 meters at a bit rate of 10³ bits per second.
    • A Hard-Wired Data Acquisition Device for Neurophysiology

      Kuhl, Frederick S.; Walter Reed Army Institute of Research (International Foundation for Telemetering, 1975-10)
      Neurophysiologic experiments are becoming increasingly numerical in nature, and may result in large quantities of data which may be practicably analyzed only by computer. A non-programmable digital controller was constructed to acquire data from a variety of remote neurophysiology experiments and to store them on magnetic tape for transport to an off-line computer. The advantages of the unit's modular design are illustrated.
    • A Review of RPV Programs in the USAF

      Palmer, John A.; US. Air Force (International Foundation for Telemetering, 1975-10)
      A brief explanation of the background behind development and employment of operational RPV systems will be followed by a resume of their accomplishments and shortcomings. Reconnaissance, electronic warfare and strike systems will be covered. The main portion of the paper will discuss systems under development to support specific missions or improve RPV capabilities in general. The Compass Cope high altitude RPV, multi-mission RPVs, expendable drones, and mini-PPVs will be considered as a family of vehicles desianed to support a variety of mission requirements. In addition, programs to improve capabilities for launch, recovery, controls and sensor integration will be included. The overall emphasis is on an appreciation for the purpose and direction of the Air Force RPV development program.
    • Tape Tracking and Handling for Magnetic Tape Recorders

      Paroby, Walter; DiSilvestre, Raymond; NASA, Goddard Space Flight Center (International Foundation for Telemetering, 1975-10)
      One of the critical performance and life limiting elements of a spacecraft tape recorder instrumentation system which has received little attention in technical literature is magnetic tape tracking and handling technology. This technology is required to understand how to gently transfer tape from one reel to another with proper alignment and a desirable uniform velocity at the read and write transducer heads. The increased demand for high data rate (i.e. multi-track spacecraft recording instrumentation systems), coupled with performance under extreme environmental conditions, requires a thorough knowledge of the various parameters which establish an optimum designed tape tracking and handling system. Stress analysis techniques are required to evaluate these parameters substantiated with test tape tracking data, to show the effect of each parameter on a tape recorder instrumentation tracking system. The technology is applicable to ground type tape recorders where the detrimental effects of edge guidance can be eliminated.
    • International Telemetering Conference Proceedings, Volume 11 (1975)

      Unknown author (International Foundation for Telemetering, 1975-10)
    • An Analog Memory Device

      Uzunoglu, Vasil; COMSAT Laboratories (International Foundation for Telemetering, 1975-10)
      The analog memory device is a combination of a bipolar and a MOSFET device which stores information in analog form for several hours or more with no degradation of data. The emitter base junction of a bipolar transistor is covered with an SiO₂ layer and a voltage is applied to this point. With zero volts applied, the unit acts as a bipolar transistor. Increasing the voltage at this point increases the emitter injection efficiency of the bipolar transistor, which in turn increases the current gain of the device. An SiO₂ layer with no leakage paths can retain the charge applied to it for long periods of time; thus the gain will remain at this level as long as the charge remains on the oxide layer. A large number of such devices can be fabricated on a single chip. Such devices combined with other integrated circuits can be used, for example, for automatic equalization of transmission lines, echo suppression, and correlation detection.
    • In-Bore Measurement of Projectile Acceleration and Base Pressure Using an S-Band Telemetry System

      Evans, James W.; Aberdeen Proving Ground (International Foundation for Telemetering, 1975-10)
      This paper presents the results of the instrumentation used on a firing test for making inbore measurements of projectile acceleration and base pressure. The system components; including the telemetry data link, acceleration and pressure sensors; and the packaging techniques are described. The data from a test of six 105mm proof projectiles fired in an M-68 tank gun are presented and compared with independent measurements.
    • New Adaptive Methods for Particles Flux Intensity Measurement Redundancy Reduction and Their Efficiency

      Evdokimov, V. P.; Pokras, V. M.; Institute for Space Research (International Foundation for Telemetering, 1975-10)
      Particles flux intensity measurements redundancy reduction algorithms are proposed. Accuracy criteria consists in limiting of a samples relative error maximum value. The algorithms are based on prediction or interpolation operations with a variable threshold, adaptive to a changing flux intensity. A formula for computation of an adaptive threshold zero order predictor compression ratio is deduced. Computed values show good coincidence with those received by signal and algorithm computer simulation. Adapter threshold zero order predictor (AT-ZOP) and first order interpolator (AT-FOI) algorithms applied to real telemetry data reveal their high efficiency as relating to attainable compression ratios. Algorithms compression ratio comparison results in predictor advantage against interpolator and unsignificantly small predictor loss when preliminary data smoothing is applied. Compression ratios for joint application of background removal [2] and adaptive predictor algorithms are also evaluated. AT-ZOP simplicity and high efficiency allow to recommend it for use in particle flux intensity measurements redundancy reduction systems.
    • Detectors Based on Conditional Tests

      Kassam, Saleem A; Thomas, John B.; Princeton University (International Foundation for Telemetering, 1975-10)
      The detection of a known signal in additive noise is an important function in many receivers. Nonparametric detectors, such as the sign detector, will result in systems with a constant false alarm rate, but usually suffer from a lower power compared to optimum parametric detectors. In this paper a conditional statistical test is used to obtain nonparametric detectors more powerful but still almost as simple to implement as the sign detector. The technique of conditional testing is therefore useful in obtaining improved detectors for practical use.