Reflection-Free Electronic Positioning System

Many electronic positioning systems, such as hyperbolic navigation and terminal guidance, suffer large errors from reflection and diffraction of their transmitted waves. The hyperbolic system described herein is free of these errors. Utilizing a pair of frequency-swept transmitters, it discriminates against reflections by separating the direct and reflected received signals into distinct sets of beat-frequency components. It is concluded that the system can suppress multipath reflections and provide flight information particularly useful in a high-density environment.