Abstract: An intrusion detection system comprises a pair of optical lenses arranged a predetermined distance apart and having overlapping fields of view within an area to be monitored to form a common field of view; at least one light-sensitive device responsive to light from each of the optical lenses; a range detector responsive to signals from the light-sensitive device and operable to determine a range to an object within the common field of view; and a range discriminator for setting at least one range gate to sense objects within the common field of view at predetermined ranges and for ignoring objects outside of the predetermined ranges.

Abstract: An intrusion detection system comprises a pair of optical lenses arranged a predetermined distance apart and having overlapping fields of view within an area to be monitored to form a common field of view; at least one light-sensitive device responsive to light from each of the optical lenses; a range detector responsive to signals from the light-sensitive device and operable to determine a range to an object within the common field of view; and a range discriminator for setting at least one range gate to sense objects within the common field of view at predetermined ranges and for ignoring objects outside of the predetermined ranges.

Abstract: A passive electro-optical range and total velocity measuring system having first and second cameras positioned along a common baseline. Control systems activate the first and second cameras at a first instance to capture a target image of a target at location T1 and at a second instance to capture a target image of the target at location T2. A range computer calculates ranges from the first camera, the second camera, and a baseline midpoint to a target at location T1 and location T2. An angles computer calculates target displacement. A velocity computer calculates total total target velocity, track velocity, and cross-track velocity. The present invention also includes a method for measuring the range and total velocity of a target using a passive electro-optical system.

Abstract: A liquid level sensor intended to be placed in a tank or sump. The Sensor includes a displacer attached to one side of an elastic plate and an optical shutter blade attached to the other side. The shutter blade contains an aperture. When the displacer is not in contact with the liquid whose level is to be measured, the aperture is positioned on the optical axis of an optoelectronic slot switch, allowing radiant energy from the emitter in the switch to irradiate the sensor in the switch. When the displacer is immersed in the liquid, a moment force is created that deforms the plate, causing the aperture to move off of the switch optical axis and the shutter blade to block the radiant energy. The elastic plate constitutes part of one surface of a liquid-tight housing. The shutter and slot switch are located inside the housing.

Abstract: A passive optical speed and distance measuring system includes a pair of camera lenses positioned along a common baseline a predetermined distance apart and controlled by an operator to capture images of a target at different times. The camera lenses are focused on light sensitive pixel arrays which capture target images at offset positions in the line scans of the pixel arrays. A video signal processor with a computer determines the location of the offset positions and calculates the range to the target by solving the trigonometry of the triangle formed by the two camera lenses and the target. Once the range to the target is known at two different times the speed of the target is calculated.