Browsing International Telemetering Conference Proceedings, Volume 04 (1968) by Title
Now showing items 47-50 of 50
Telemetry with Unrestrained AnimalsTelemetry from animals in their natural environment requires simple but efficient data coding methods. The problems common to behavioral or physiological studies with wild animals include immobilization techniques, harness design and ruggedized instrumentation development. Radio tracking experiences with the lion, elephant and buffalo and other game animals are summarized and an outline of instrumentation requirements for a study of long range goal finding ability in the green sea turtle is presented.
Tranmission of Cardiovascular Data from DogsProlonged acquisition of dynamic blood pressure data from animal subjects in various experimental conditions has become a special research area in numerous institutions. To properly conduct many of these experiments, the subject must be instrumented with blood pressure sensors and a means of conveying the indicated pressure level to a remote station. Quite often data must be obtained over several weeks in which recalibration can not be conducted. Telemetry techniques are quite adaptable to these problems and in many instances are the only solution available. To illustrate the special applications of telemetry, several experiments are described along with the hardware required to conduct these experiments.
A Two-Channel Monopulse Telemetry and Tracking Antenna FeedThe two-channel monopulse telemetry and tracking antenna feed operates over the frequency range from 1435 to 2300 MHz. The feed was designed and developed for a 7-foot parabolic reflector located in the nose cone of an EC-135N aircraft. This airborne system maintains in-flight voice and telemetry communications with Apollo spacecraft during the injection and reentry phases of the Apollo missions. The feed consists of a planar multimode dual-polarized cavity-backed spiral radiator and two printed circuit comparators. The spiral radiator is excited in the sum and difference modes at both its inner and outer filament terminals. This allows the simultaneous reception of right-hand and lefthand circularly polarized signals. The sum and difference modes of excitation are precisely controlled to provide the proper reflector illumination functions for improved sidelobes and efficiency. Sidelobe levels in excess of 22 db, null depths greater than 40 db, boresight shifts of less than 0.25 degree, and system efficiencies of greater than 40 percent have been achieved.
Wideband PCM-FM Bit Error Probability Using Discriminator DetectionThe expression for bit probability of PCM/FM is derived for a receiver with an IF bandwidth equal to or greater than the data rate, limiter-discriminator detection; followed by a post-detection filter with bandwidth equal to the data rate. The optimum deviation ratio is shown to be essentially constant regardless of the IF bandwidth-to-data rate ratio and system performance is shown to degrade when this ratio is greater than unity. Pre-modulation filtering of the transmitted PCM data is experimentally tested and the analytical results are shown to good agreement with experimental data.