Abstract: A dual signature perimeter detection system utilizing an elongated solenoid ype transducer having a ferromagnetic core as a line sensor is buried in the ground around an area to be protected against intrusion. One end of the transducer is impressed with constant frequency oscillator signals from a signal generator, while a resistance load impedance is connected across the other end of the transducer at the input side of an amplifier used to pass amplified signals selectively to the inputs of either a bandpass type filter or an A.M. detector, or to both simultaneously, then to their related alarms. The line sensor is sensitive to both magnetic and strain stimuli, but the system hereof, which utilizes dual alarm devices, not only provides for determining the type of stimulus creating the signals, but also improves the sensitivity and response uniformity of the transducer.

Abstract: An electronic ferroelectric length measuring transducer and system for obtaining information and read-in of that information visually to determine the length of an image as well as means to determine if a target is moving. These actions are done very quickly and accurately by changing the polarization of a ferroelectric substrate. In addition, the information, once obtained, can be stored indefinitely without recourse to any external stimuli circuitry, until readout.

Abstract: A wedge of ferroelectric material is used as a thermal imaging transducer by plating a multiplicity of signal generating electrodes to the surface of the ferroelectric wedge. The wedge is electronically polarized using a descending voltage and thermal images are read out of the transducer using an ascending voltage ramp of opposite polarity from the polarizing voltage. Readout is obtained without requiring mechanical panning or thermal image interruption even if the subject is stationary.