Abstract: A method and system are provided for detecting objects at or below a surf of a body of water. A focused beam of amplitude varying electromagnetic radiation, e.g., a pulsed laser beam, is directed through the air towards the water's surface. Acoustic energy under the water's surface is monitored for any acoustic return that may be generated in the water as a result of the beam being incident on either an object at the water's surface or the water's surface above an object.

Abstract: A plurality of drive modules positioned at spaced locations along a drive th of a driven member respectively include two magnetostrictive rod elements in alignment with each other, with adjacent ends thereof in engagement with a third magnetostrictive rod element extending transversely of the drive path to engage the driven member. Simultaneous elongation and contraction of the two rod elements during elongation of the third rod element in the drive modules imparts unidirectional motion to the driven member.

Abstract: A pulse of luminant energy of short duration is reflected from a target as n echo source of both two dimensional target imaging data and target depth distance data by optical gating of the echo pulse at one receiving location. The pulse is thereby divided into image depth slices under control of timing signals in order to extract therefrom three dimensional imaging data during its short duration.

Abstract: Propagation of modulated radiation from a platform is substantially limited o unidirectional transmission through a body of water. Acoustical energy is generated at the surface of a remote object submerged in the water in response to impingement and absorption of the modulated radiation from the platform. Radiation of the acoustical energy generated adjacent the object is detected at the platform to extract data therefrom from which the location of the object relative to the platform is indicated.

Abstract: This discloses an improved side-scan sonar capable of locating objects on e ocean floor including the strip directly beneath the sonar transmitter and receiver, which in prior arrangements had to be obtained by another pass. The arrangement includes a platform having acoustic transmitters spaced apart a substantial distance on either side of acoustic receivers. The transmitter on the right directs its acoustic output to the left and the transmitter on the left directs its acoustic output to the right for increased shadow forming and enhanced detection by the receiver of objects of height directly beneath the receiver.

Abstract: A laser intrusion system incorporating a relatively long wavelength infra-red laser, a beam path, a quantum amplifier, a detector, and associated optical and electronic components is described. The relatively long wavelength of the laser radiation and the high gain and narrow bandwidth of the quantum amplifier make the system relatively immune to environmental conditions such as fog and rain and particularly applicable for long range, all-weather, outdoor use.