GPS-Based System Tracks Relative Position of Two Airplanes

A developmental electronic system that includes Global Positioning System (GPS) receivers is designed to track the relative position and velocity to two airplanes in real time. In the original application for which the system is being developed, one F-18 airplane (denoted the "chase vehicle") is to be used to take schlieren photographs of shock waves generated by the another F-18 airplane (denoted the "target vehicle"). When fully developed, the system would afford the precise position and time measurements needed to accomplish the schlieren shock-wave photography.