Abstract: A method and apparatus for monitoring moving vehicular traffic, especially adapted for the detailed profiling and counting of airport usage by aircraft employing Doppler radar and sound generated by target aircraft. A primary parabolic reflector operated in the Cassegrainian mode with respect to Doppler radar radiation, employed in combination with a hyperbolic sub-reflector constructed so that it will reflect the radar radiation but remain transparent to sound waves is used to propagate and receive radar radiation, and to receive sound waves emanating from a target aircraft. Sound waves emanating from the target are received by the parabolic reflector and directed toward the parabolic reflector's primary focus where they strike a microphone placed at the primary focus of such reflector. The signal from the microphone and the information from the Doppler radar unit are processed by a central processing unit to provide a variety of information relating to the target aircraft.

Abstract: A method and apparatus for monitoring moving vehicular traffic, especially adapted for the detailed profiling and counting of airport usage by aircraft employing Doppler radar and sound generated by target aircraft. A primary parabolic reflector operated in the Cassegrainian mode with respect to Doppler radar radiation, employed in combination with a hyperbolic sub-reflector constructed so that it will reflect the radar radiation but remain transparent to sound waves is used to propagate and receive radar radiation, and to receive sound waves emanating from a target aircraft. Sound waves emanating from the target are received by the parabolic reflector and directed toward the parabolic reflector's primary focus where they strike a microphone placed at the primary focus of such reflector. The signal from the microphone and the information from the Dopple radar unit are processed by a central processing unit to provide a variety of information relating to the aircraft.

Abstract: A resistor electrode type touch sensor having enhanced area of linear response by reducing the bow in perimeters of the sensor. Within a resistive layer of substantially uniform resistivity orthogonal electrical fields are produced to give coordinates of a selected position. Overlying, but spaced from, the resistive layer is an optional flexible conductive pick-off sheet facing the resistive layer which will contact the resistive layer when touched at a selected position. Other elements are described to obtain signals corresponding to the coordinates of a selected point. A resistance element is positioned proximate the perimeter of the resistive layer made up of discontinuous conductive lines applied to the resistive layer. For a given value of the resistive layer, the value of the resistance element is determined by the length and width of any gaps between the conductive lines.