Abstract: A directional hydrophone comprises a plurality of coil elements each disposed in an air gap in a common magnetic circuit. In a first embodiment of the invention two coil elements each have a single degree of freedom of motion which is orthogonal to the other. The force due to an acoustic wave impingent upon the hydrophone is resolved into two orthogonal components by the two coils which give rise to two distinct electrical output signals proportional to the sine and cosine respectively of the angle at which the acoustic wave arrives. In another embodiment of the invention each coil element has two degrees of freedom of motion and the movement of each of the coil elements is resolved into two orthogonal components by the effective length of the coil which varies in a known manner with the angle of coil motion with respect to the polarity of the magnetic circuit.

Abstract: 1. In a method for communicating information between a submerged vessel and a buoy, the improvement comprising the steps ofA. allowing said buoy to assume substantially the same horizontal velocity as the water in which it is floating,B. feeding out a communication cable interconnecting said buoy with said vessel at substantially the rate at which the distance between said vessel and said buoy increases,C. destroying said buoy upon command, andD. releasing the fed-out cable from said vessel.

Abstract: An aquaculture rearing system for improving space utilization and yield is disclosed in which clustered, vertical rearing tanks are provided with individual stacked habitats in the form of baskets attached to a strongback member which houses a removable feeding rod, in which the baskets are quickly detachable through the use of interlocking detents and in which nestable baskets are utilized for different sized animals. Progressive space increments to match growth are provided by two different size baskets and removable dividers. Overflow water is skimmed by a skimmer which surrounds the entire top of each tank to prevent bacteriologic contamination of the water within the tank. The staggered modular mounting produces a tripod-like stability even though each tank has a single leg, and provides visibility and density. An overhead materials handling system is used in which the animals are protected by a fog to prevent gill malfunction.

Abstract: Apparatus is provided to permit the control of circuitry within a video game generator including an audio playback device employing an audio tape or phonograph disc having recorded thereon digital data which is decoded and interfaced with the video game generator.

Abstract: In one embodiment, cooling of a laser passive Q-switch is provided by affixing the Q-switch to the rear mirror of the laser which, thus, acts as a heat sink for the Q-switch.

Abstract: Inertial measurements, including the measurement of angular velocity as well as angular and translational acceleration, are made by spinning one or more translational acceleration transducers disposed at predetermined positions and orientations and combining their output signals. The principles of the invention are also applied to generate components of translational acceleration for the purpose of calibrating translational acceleration transducers.

Abstract: Discrimination of long range targets from short range targets is provided by generating a vertical dipole beam and a narrow uni-directional horizontal beam which may be steered. Targets in the dipole beam are short range targets whose acoustic signals arrive at angles to the horizontal plane, whereas long range targets are those in the horizontal beam, since acoustic signals from long range targets come in on the horizontal plane.

Abstract: A television message system is disclosed wherein encoded data displayed on a small area of a television screen is received by a photosensitive pickup which responds to the encoded data, and including a message processor for storing viewer selected data and processing such data for redisplay on the television screen as readable alpha-numerics.

Abstract: A tilt compensated transducer array is provided with omni-directional transducers, compensated bi-directional transducers, and a processor which forms omni and bi-directional beams that are combined to cancel image lobes to give the array a uni-directional characteristic in which but a single, steerable main lobe is formed over a board range of steering angles. When the elements are located along a flexible line about which they naturally twist, a pair of orthogonally oriented bi-directional transducers is tilt or twist compensated to make image lobe cancellation possible. This is done by a compensator at each pair of bi-directional transducers which modifies their outputs in accordance with the deflection angle from the local vertical so as to obtain an output signal substantially the same as would be obtained by a single, properly oriented bi-directional transducer. Additionally, the use of a tilt compensated element permits discrimination of long range targets from short range targets.

Abstract: A transducer array is provided with omni-directional transducers, bi-directional transducers, and a processor which forms omni and bi-directional beams that are combined to cancel image lobes to give the array a uni-directional characteristic in which but a single, steerable main lobe is formed over a broad range of steering angles.

Abstract: A privacy communication system is herein disclosed comprising apparatus for digitizing information to be transmitted, apparatus for logically adding a selected pseudo-random digital code to the digitized information, apparatus for removing the pseudo-random code upon reception and apparatus for synchronizing the transmitted and received pseudo-random codes.

Abstract: A capacitor goniometer type tilt compensator is provided for the bi-directional elements in a transducer array in which each pair of bi-directional transducers is tilt or twist compensated to make image lobe cancellation possible. This is done by a specialized capacitor goniometer type compensator at each pair of bi-directional transducers which modifies their outputs in accordance with the deflection angle from the local vertical so as to obtain an output signal substantially the same as would be obtained by a single, properly oriented bi-directional transducer.

Abstract: Attenuation of a signal is achieved by biphase modulating the signal with an asymmetrical duty factor rectangular wave. In one embodiment of the invention an input signal is applied to a phase reversal switch having as its second input thereto an asymmetrical duty factor rectangular wave.

Abstract: Wavelength diversity in solid state lasers is achieved by providing a single laser rod comprising a host material and two different active ion species wherein each of the active ions also sensitizes the other active ion.The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of the Air Force.

Abstract: Improved radar system performance in a jamming environment is achieved by applying the received signal containing both the desired radar signal and a higher level FM jamming signal to a radar receiver only during the time when the instantaneous frequency of the jamming signal is not at or within prescribed limits of the radar frequency.

Abstract: Optical detecting and ranging equipment of high information gathering and processing capacity employs a pulsed coherent source illuminating with each pulse a line field of view. An optical receiver monitoring the entire field of view has a scanner that causes reflections received at different times to be recorded at correspondingly different coordinates.

Abstract: An inertial measurement device comprising a rotatable member having a fluid-filled chamber closed by a resilient member responsive to the forces acting on the fluid and a modulator coupled to the resilient member to alter the radiation from a light source to a detector depending upon the response of the resilient member.

Abstract: Apparatus for generating horizontal and vertical synchronization signals in synchronism with synchronization signals generated by an ongoing television program received by a user without internal connections to the user's television receiver, is provided by optically extracting pulses from a displayed raster of the ongoing television program and generating therefrom the synchronization signals in synchronization with the ongoing program.

Abstract: A room temperature, optically pumped, solid state laser operating at 0.75 micrometers including a Ho.sup.3+ :LiYF.sub.4 crystal provides an excellent source for optical target location systems and other applications which require a source of high peak power in the spectral region just beyond the visible - the "Deep Red".

Abstract: A single reticle is provided having spectral and spatial filtering characteristics such that it may be employed in radiation responsive systems for both passive tracking and active tracking employing a laser target designator.