• A 2-kw S-Band Re-Entry Telemetry System

      Trapp, D. L.; Williams, P. K.; Sandia Laboratories (International Foundation for Telemetering, 1971-09)
      Instrumentation of high-velocity re-entry rocket systems at Sandia Laboratories has been complicated because of dependence on onboard magnetic tape recorders to store data until the carrier emerges from the radiofrequency blackout. This paper describes an approach designed to minimize the effect of the RF blackout by means of employing a sampled data system the output of which consists of 1-μsec pulses of 2-kw RF power level. The effort was initiated in the spring of 1970 for the purpose of obtaining real-time data during the re-entry blackout phase of a Sandia re-entry flight test. Re-entry velocities in the vicinity of 25,000 fps are expected.
    • Intermodulation Effects in FDM Telemetry Systems

      Johnson, C. S.; Sandia Laboratories (International Foundation for Telemetering, 1971-09)
      The performance of a telemetry system is affected by three principal sources: the noise of the electronics, the noise of the transmission link, and the intermodulation noise. Intermodulation noise is a significant contributor to signal-to-noise ratio of a telemetry system and can sometimes be more serious than the other noise sources. The experimental results described in this paper are aimed at showing how serious the intermodulation noise can be to a multichannel telemetry system.
    • A Shock Hardened Delayed Transmission System for Transient Data Acquisition

      Bentley, R. D.; Fritz, R. L.; Sandia Laboratories (International Foundation for Telemetering, 1971-09)
      A shock hardened, delayed transmission PCM system for use in an artillery projectile instrumentation program is reported. The output of the projectile mounted PCM encoder is coupled to an MOS shift register memory to delay data transmission until projectile flight, thus eliminating the requirement for a real-time transmission link for in-barrel data. The capabilities to monitor both in-barrel phenomena and flight performance parameters are included. Windowing of the transient, in-barrel data is accomplished by threshold discrimination within the projectile mounted system. System design, operation and ground support requirements are discussed with flight test results presented.
    • A Versatile Memory Controlled PCM Encoder for Adaptive Telemetry Systems

      Johnson, C. S.; Sandia Laboratories (International Foundation for Telemetering, 1971-09)
      An Adaptive Telemetry System is defined as a flexible, controllable pulse code modulation (PCM) telemetry system which offers many options and many modes of operation prior to and during actual test of a monitored system. The concept of having a telemetry system adapt to the data and circumstances of the test is not new. Large data-gathering systems using computers for control have pioneered this concept. However, the present development activity has centered on a small aerospace memory controlled PCM encoder which can function as the keystone of an adaptive telemetry system. The encoder can be used by itself as a general-purpose airborne encoder.