• DESIGN OF A GPS/TELEMETRY ANTENNA FOR SMALL DIAMETER PROJECTILES

      Ryken, Marv; Davis, Rick; Kujiraoka, Scott R.; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2000-10)
      In the past, airplanes, target drones, pods, and large missiles have been instrumented with telemetry, flight termination and beacon tracking antennas to assess performance. With the emerging use of the Global Positioning System (GPS) for tracking purposes, GPS is also included as part of the instrumentation package. This paper addresses the design of a conformal wraparound antenna system to cover the telemetry and GPS L1 frequencies for a small (2.75 inch) diameter airborne projectile. A filter is also integrated into the antenna system to isolate the transmitted telemetry signal from the received GPS signal. This integration is necessary due to the lack of space in the small diameter projectile. Performance characteristics of the prototype antenna system are also presented.
    • EVALUATION OF GPS RECEIVER PERFORMANCE UNDER HIGH DYNAMIC CONDITIONS

      Cunningham, James P.; Khoe, Paula K.; Hermann, Bruce R.; Evans, Alan G.; Merts, John H.; Naval Surface Warfare Center Dahlgren Division; USAF Air Armament Center (International Foundation for Telemetering, 2000-10)
      Global Positioning System (GPS) sensors have the potential to provide precise position, velocity, and timing information in high dynamic applications. Missile flight-testing is one such application where accurate relative positions are important. GPS instrumentation can provide the high accuracy while offering both significant cost savings and improved confidence in the test results when compared to existing methods. To date, the use of GPS in missile flight-testing has been limited due to a lack of demonstrated GPS receiver tracking capability in high dynamics. This paper evaluates several currently available GPS receivers for both their tracking capability and their measurement accuracy in high dynamic environments.
    • AN INTEGRATED APPROACH TO ROBUST FLIGHT TERMINATION FOR SMALL MISSILE TEST AND TRAINING RANGE USE

      Alves, Daniel F. Jr; Alpha Instrumentation And Information Management (International Foundation for Telemetering, 2000-10)
      This paper will investigate the areas that must be addressed to implement a truly integrated Range instrumentation system on a GPS-based Range, using a patented L-Band commanding scheme. Hardware issues will be highlighted as well the issues to be addressed in changing from an audio tone-frequency modulated command system to a digital system incorporating encryption and spread spectrum. Some thoughts addressing costs and schedule to incorporate this approach into the architecture of Joint Advanced Missile Instrumentation (JAMI) program are also presented, as well as a discussion of the benefits to be accrued over the existing system.
    • NEAR-FAR RESISTANT PSEUDOLITE RANGING USING THE EXTENDED KALMAN FILTER

      Iltis, Ronald A.; University of California (International Foundation for Telemetering, 2000-10)
      Pseudolites have been proposed for augmentation/replacement of the GPS system in radiolocation applications. However, a terrestrial pseudolite system suffers from the near-far effect due to received power disparities. Conventional code tracking loops as employed in GPS receivers are unable to suppress near-far interference. Here, a multiuser code tracking algorithm is presented based on the extended Kalman filter (EKF.) The EKF jointly tracks the delays and amplitudes of multiple received pseudolite waveforms. A modified EKF based on an approximate Bayesian estimator (BEKF) is also developed, which can in principle both acquire and track code delays, as well as detect loss-of-lock. Representative simulation results for the BEKF are presented for code tracking with 2 and 5 users.
    • A STATUS REPORT OF THE JOINT ADVANCED MISSILE INSTRUMENTATION PROGRAM AN OFFICE OF THE SECRETARY OF DEFENSE CENTRAL TEST AND EVALUATION INVESTMENT PROGRAM INITIATIVE

      Scofield, Don; Powell, Dave; Naval Air Warfare Center Weapons Division (International Foundation for Telemetering, 2000-10)
      Joint Advanced Missile Instrumentation (JAMI), a 1997 new-start multi-year Central Test and Evaluation Investment Program (CTEIP), is developing advanced telemetry system components that can be used in an integrated instrumentation package for tri-service small missile test and training applications. JAMI will provide telemetry, Time-Space-Position Information (TSPI), flight termination and end-game vector scoring in a low cost, modular package that will allow world-wide test and training- eliminating, in most cases, the need for range-specific (or multi-system) facilities. JAMI will incorporate Global Positioning System (GPS)-based technology as the TSPI and vector scoring engine, and is completing the development of a solid state programmable safe and arm device for flight safety applications. The JAMI program has progressed into Phase 2 and full-scale development of advanced GPS technologies. This paper discusses the progress of the program during the past year and the efforts planned for fiscal year 2000. Testing of GPS receivers and problems encountered in programming GPS simulator for missile flight profiles are discussed.