A Guided Radar System for Obstacle Detection

This paper describes the operation of a guided radar system capable of detecting human targets or other obstacles along a guideway at ranges up to a quarter of a mile. The concept is based on the use of so-called leaky coaxial cables which were first developed for the communications field. Two cables, installed on either side of the guideway, act as the medium of propagation in the form of a surface waveguide. The instrument detects the presence of obstacles which perturb the EM field induced in the guideway. The system is centered around a minicomputer which controls the transmission of RF pulses down the guideway and the reception of the return signal. The computer also performs further processing of the return signal in the form of integration, filtering, and removal of stationary clutter, the result being a very sensitive instrument. Results of experiments are presented which demonstrate the usefulness of this instrument in determining the important electromagnetic characteristics of leaky cable waveguides.