• WHITE SANDS MISSILE RANGE (WSMR) A PHASE - DIFFERENCE MEASURING TRACKING SYSTEM

      PARRA, MARIO Z.; National Range Operations Directorate (International Foundation for Telemetering, 1982-09)
      The Phase Difference Measuring (PDM) system is an RF interferometer object tracking system which utilizes the object’s radiated telemetry power spectra for tracking purposes. The PDM system is being developed in-house at White Sands Missile Range as a highly mobile electronic angle measuring system, to augument existing position measuring capability in range instrumentation systems. The system is comprised of two Remote Data Acquisition Stations (RDAS) and a Cosine Conversion Facility (CCF). Each RDAS is comprised of two antenna arrays configured as crossed baselines. The RDAS equipment utilizes high speed RF switching in a time sharing technique designed to reduce the amount of hardware required at the remote sites to produce direction cosines. The CCF collects two direction cosines from each RDAS, it then transforms the direction cosines to position data for subsequent transmission to a Range Control Center. This paper will provide basic system theory, explain the proposed antenna PF switching techniques, and also the computer simulation analysis for a baseline consisting of two pair of antennas.
    • WHITE SANDS MISSILE RANGE (WSMR) TELEMETRY TRACKING IMPROVEMENTS

      Pedroza, Moises; White Sands Missile Range (International Foundation for Telemetering, 1982-09)
      The WSMR Telemetry Tracking Systems consist of ten (10) automatic trackers and four (4) manual trackers. These trackers operate in the frequency ranges of 1435 to 1540 MHz and 2200 to 2300 MHz. Two Telemetry Acquisition Systems (TAS) with 24-foot parabolic antennas are located at fixed sites. A 6-foot parabolic antenna system has been converted from a mobile unit to a fixed-site system. Seven Transportable Telemetry Acquisition Systems (TTAS) with 8-foot parabolic antennas can be located on and off the range along with a mobile microwave relay station to support range tests. The RF subsystems on the seven TTAS’s have been miniaturized and integrated with the feed assembly resulting in a vast improvement in autotrack reliability. The digital slave tracking capability of the seven TTAS’s and two TAS’s has been improved by a joint effort between two WSMR organizations. Tracking System Interface (TSI) hardware and software were both developed in-house at WSMR by the Instrumentation Directorate. The National Range Operations Directorate, Data Collection Division, Telemetry Branch interfaced and installed the TSI to the tracking systems. The TSI utilizes two (2) Z80 microprocessors and is capable of slaving to instrumentation RADAR data in one of two modes. The first mode is dependent on the UNIVAC 1108, WSMR real-time computer complex, to convert the RADAR XYZ data to site oriented azimuth and elevation data. The second mode allows the telemetry trackers to accept RADAR XYZ data directly and perform its own coordinate conversion. An additional feature of the TSI is the test mode for self-checks, servo tests, and system readiness tests.
    • WIDEBAND MODEM CHARACTERIZATION TESTING

      Finn, Gerald T.; The Aerospace Corporation (International Foundation for Telemetering, 1982-09)
      As part of an investigation into the causes for random, unexplained data “dropouts” on a Defense Satellite Communication link between the Air Force Satellite Control Facility, Sunnyvale, California and the Indian Ocean Remote Tracking Station, a number of tests were conducted to characterize the performance parameters of the wideband modems used on the link. These tests were used to measure the loop parameters of the modem Carrier and Timing Recovery Loops and to determine the modem sensitivity to RF phase disturbances, data rate variations and various repetitive bit patterns. This paper describes the test techniques used and the results obtained.