• VANGUARD/PLACE EXPERIMENT SYSTEM DESIGN AND TEST PLAN

      Taylor, Ralph E.; National Aeronautics and Space Administration (International Foundation for Telemetering, 1973-10)
      A system design and test plan are described for operational evaluation of the NASA-Goddard Position Location and Aircraft Communications Equipment (PLACE), at C-band (4/6GHz), using NASA’s ship, the USNS Vanguard, and the ATS-3 and ATS-5 synchronous satellites. The Sea Test phase, extending from March 29, 1973 to April 15, 1973 has been successfully completed; the principal objectives of the experiment were achieved. Typical PLACE-computed, position-location data is shown for the Vanguard. Position location and voice-quality measurements were excellent; ship position was determined within 2 nmi; high-quality, 2-way voice transmissions resulted as determined from audience participation, intelligibility and articulation-index analysis. A C-band/L-band satellite trilateration experiment is discussed.
    • A VIDEO BANDWIDTH HE-NE LASER COMMUNICATION SYSTEM

      Pao, Yoh-Han; Freeman, J.P.; Allen, J.W.; Claspy, P.C.; Laser Communications Inc.; Case Institute of Technology (International Foundation for Telemetering, 1973-10)
      A He-Ne laser communication system with video bandwidth capability is described. The system is suitable for the transmission of video signals generally compatible with U.S. commercial practice, and the transmission of digital data at rates of approximately 10 to 1000 Kb/s, over ranges extending from a few hundred feet to about 10 miles. Relative to cable systems and microwave links, this laser system has the advantages of immunity from electromagnetic noise and from microwave interference, ease of installation, comparative freedom from regulation, mobile operation and lower costs. Possible occasional outages due to inclement weather constitute the principal drawback. This system is different from two other available types of optical links. The light emitting diode (LED) links are limited to short ranges and the laser injection diode (LID) links have low duty cycles and are not designed for video capability. The performance characteristics and operating data of a specific system, the LCI-203 system of LASER COMMUNICATIONS, INC. , are described in detail. Operating ranges and corresponding reliability figures are estimated for various geographical locations. Operating experiences in health care delivery and security surveillance applications are described.