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 circuit for controlling the switching of a high-power diode microwave switch with a relatively low-power diode switching circuit by utilizing a high-power quadrature hybrid coupler in the switch with the switch input and diode switching element being connected to one leg of the coupler, the output of the switch being connected to a second leg of the coupler, the third and fourth legs of the coupler being capacitively grounded to provide an a-c short at RF frequencies and thereby reflect microwave energy back into the switch, and a switch control circuit being connected to the third leg of the coupler. The coupler divides the power input to the switch so only a portion thereof is incident on the diode switch control circuit, and thus provides isolation between the control circuit and the switch input and output.

Abstract: A method of adapting a miniature standard coaxial connector to enable the coupling of a fiber optic cable to an active device is disclosed in which the female portion of the connector is partially disassembled by removing its central contact and modified by drilling out or otherwise enlarging the passage which is left after the removal of the contact. The active device is mounted through a hole drilled in a printed circuit board, and electrically coupled to the top layer thereof. This unit is then affixed to the end of the female connector carrying the enlarged passage, such that the metalized layer on the printed circuit board makes electrical contact with the metal casing of the female portion of the connector, and such that the face of the active element is exposed through the enlarged passage.

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: A method and apparatus are provided for sorting signals from compressive receivers in accordance with the type of modulation on the signal, so as to be able to establish the identity of the signal short of fully demodulating it. It has been found that signals from a compressive receiver which are insufficiently sampled for complete demodulation can be identified by "histograms" in which each designated condition, such as the number of consecutive 1's or 0's is graphed against the number of occurrences of this designated condition over a period of time, designated a "data collection interval." The result is a pattern or diagram which is characteristic of the modulation type, such that FSK, DFSK, PSK, hand morse, machine morse, anomolous morse, AM, SSB, and multitones can be distinguished one from another. Moreover, it is possible to recognize two-way voice communication.

Abstract: A diode microwave switch is disclosed having both low power dissipation loss and a low voltage standing wave ratio by the techniques of mounting microwave diodes on pedestals and interconnecting them with air line microstrip connections and utilizing special impedance matching techniques. Voltage standing wave ratios of 1.15:1.00 with 0.3 db loss in a three diode 60 db isolation switch are readily obtained.

Abstract: LORAN-C navigation equipment is disclosed wherein digital circuitry is used to automatically distinguish a master LORAN-C transmitting station from a secondary station. The equipment operator manually enters approximate time difference of signal arrival information for a particular secondary station into the equipment after consulting a LORAN-C chart. The operator then manually determines the exact time difference of arrival using thumbwheel switches and a LED lamp display. This procedure is repeated to determine exact time difference of arrival information for the master and each selected secondary station, and the information is plotted in a well-known manner on the LORAN-C chart to locate the position of the craft upon which the equipment is located. Manual acquisition of secondary stations simplifies the equipment and eliminates interference problems caused by skywaves and other transmissions.

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: A unitary double-halved shipping container is provided with a wheel well, and detachable arms and wheel assembly to convert the container into a wheelbarrow configuration. This permits ease of handling and maneuvering at low cost in view of the quickly detachable arms and wheel assembly. Integral slots are provided in the container body which accommodate the prongs of a conventional fork lift truck should movement of a number of containers be desired or should the distance of movement be such as to be more conveniently done by fork lift machinery. The halves of the containers are nestable and the slots accommodate securing or shipping straps. The wheel assembly includes a U-shaped spring member, the ends of which are brought together for ease of insertion and release of the wheel. The U-shaped spring member is also provided with a number of outwardly projecting sharp protrusions to secure the wheel assembly to the container when the ends of the U-shaped member are released.

Abstract: A solar energy conversion system is provided which includes a black body receiver for transferring energy from focused solar radiation to a circulating gas. The receiver includes a honeycomb heat exchanger located within a chamber sealed with impingement cooled windows, the outermost one of which acts as a one way trap or diode to prevent energy radiated by the heated honeycomb from escaping to the atmosphere. The heat exchanger is formed with a number of tubes which are oriented to be illuminated "end on" for minimizing retroreflection of the incoming energy. Because of the "end on" orientation, a large majority of the incoming energy impinges on the internal walls of the tubes and is internally reflected until it is absorbed. Cool gas, which may be air, is introduced into the receiver under pressure such that the gas passes through the tubes of the heat exchanger where it is heated to temperatures that are typically in the vicinity of 1700.degree. F.

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: A satellite relay communications system includes a ground relay station arranged so that each message from one subscriber to another is relayed by the satellite relay to the ground relay, processed by the ground relay and then transmitted to the second subscriber by way of the satellite relay. Processing at the ground relay station includes a switching function in which the carrier frequency of each message is changed from the frequency used for transmitting by the subscriber sending each message to the frequency used for reception by the subscriber to whom the message is addressed. This permits each subscriber to use a single transmitting frequency and a minimum number of receiving frequencies.

Abstract: An improved long-life design for solar energy receivers provides for greatly reduced thermally induced stress and permits the utilization of less expensive heat exchanger materials while maintaining receiver efficiencies in excess of 85% without undue expenditure of energy to circulate the working fluid. In one embodiment, the flow index for the receiver is first set as close as practical to a value such that the Graetz number yields the optimal heat transfer coefficient per unit of pumping energy, in this case, 6. The convective index for the receiver is then set as closely as practical to two times the flow index so as to obtain optimal efficiency per unit mass of material.

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.