Abstract: An excited state polarization altering optical filter includes a vapor cell having a population of electrons with a plurality of energy levels that receive light and transmit light according to the received light. A first pulsed dye laser applies a beam of light by way of a circular polarizer to provide a first beam of light having a first polarization to the vapor cell. The first beam of light causes transitions of the electrons from one energy level to another energy level. A second pulsed dye laser applies a second beam of light with a second, differing, linear polarization to the vapor cell. The vapor cell differentially transmits the first and second beams of light in accordance with the differing polarizations. A delay path is provided for delaying the second beam of light before the second beam of light is applied to the vapor cell. The delay path is tuned by adjusting the length. A third laser applies a beam of light to the first and second lasers. The third laser may be an Nd:YAG laser.

Abstract: At least a part of a first coherent beam of monochromatic light is incident bliquely on the reflecting surface of a mirror to produce a reflected beam in a direction different from that of the first beam. An interference pattern is produced within a volume defined by the intersection of the reflected beam with the first beam. A part of an optical fiber is positioned in the volume containing the interference pattern, and a grating is photo-induced in the optical fiber by exposure of the optical fiber to the interference pattern. A desired Bragg period in the grating can be selected by tilting the mirror to change the interference pattern.

Abstract: This invention relates to an on-line statistical process control device for solder paste and residues. The invention consists of electronics hardware, software, and probing systems. The electrical hardware of the invention provides voltage and current measurements of solder paste materials, the software of the invention controls the hardware, provides real-time complex, nonlinear least squares curve fitting for equivalent circuit analysis, data storage and retrieval of circuit parameters and behavior, and statistical process control tracking and charting. The probing systems of the invention allows for 2, 3, and 4 probe surface and bulk measurements of the solder paste and residues.

Abstract: A nondestructive method and apparatus for optical detection and monitoring corrosion in structures normally inaccessible to light and observation. An optical fiber coated with a corrosion sensitive compound is embedded in the structure. Tapped Bragg gratings of different Bragg periods are spaced along the fiber and refract a narrow bandwidth component of a broad beam light pulse transmitted through the fiber. Due to corrosion, the refracted components are reflected by the compound and their amplitudes are detected and displayed for each narrow bandwidth.

Abstract: Reciprocity calibration of electromechanical transducers is carried out with three transducers, which are secured to a mass mounted for oscillation as a pendulum. A first transducer is driven and the electrical output of a second transducer is measured. A third transducer, which must be a linear, reciprocal device, is driven and the electrical output of the second transducer is measured. The first transducer is driven while the electrical output of the third transducer is measured. The sensitivities of the transducers can be deduced from the electrical inputs and the measured electrical outputs by taking advantage of reciprocity. The transducers may be mounted to the pendulum mass two at a time, or alternatively, all three transducers may be fixed to the pendulum mass.

Abstract: A sensor and method are disclosed for determining if a region, defined by two end points, in a structure has exceeded a predetermined amount of strain. The sensor has an optical waveguide which has two ends for receiving and emitting light and which is fixable at two locations thereon to respective ones of the end points to define a sensing region therebetween. The sensing region has a first portion with a first length and a first cross-sectional area, and a second portion with a second length and a second cross-sectional area which is smaller than the first cross-sectional area. The lengths and cross-sectional areas are sized so that the optical waveguide has a strain failure point equal to the predetermined amount of strain. The lengths and cross-sectional areas are approximately sized according to the formula R=.alpha.+1/ (.alpha./.beta.

Abstract: A tapped Bragg grating is used to demodulate optical signals reflected by ber optic Bragg gratings in a sensor in which the line spacings in the fiber optic Bragg gratings vary in response to a mechanical stress. A light detector, or light detector array is used to detect variation in the angular pattern of the light scattered by the tapped Bragg grating. Arrangements of mirrors, or alternatively arrangements of lenses, are used to concentrate the scattered light toward the light detectors and to enhance the angular changes in the scattered light.

Abstract: A variable focus adapter is disclosed that comprises the combination of a ns and an aperture provided by a plate all lodged in a housing that is placed so that the lens is in proximity with each objective lens of a binocular arrangement to change the focal range from greater than 20 ft. to seven (7) ft. with a depth of field spanning from 5 to 15 ft.

Abstract: A cross-corrugated panel has a core between two faceplates, where the core omprises two groups of corrugated elements that are perpendicular to each other. The corrugated elements have peaks and troughs connected by diagonally-extending segments. In each group of corrugated elements the peaks and troughs in adjacent elements are 180 degrees out-of-phase with each other. The faceplates and the corrugated elements in each group are joined at the peaks and troughs. The diagonally-extending segments of one of the elements comprise flat strips whose flat surfaces are parallel to each other and perpendicular to the faceplates. To make a cross-corrugated panel, a first group of elements is provided, each element being formed by oppositely winding two strips of curable material to form overlapping helixes having rectangular cross-sections. The elements are positioned in parallel. A second group of elements of curable material is placed perpendicular to the first group of elements.

Abstract: A portable antenna control unit that operates a radar antenna and simulates arious control signals that are generated by a fire control radar. The antenna control unit can be interfaced to a standard commercial, portable computer, or it can be portable, stand-alone unit, manually controlled and easily transported to a test range. Both embodiments diagnose problems in an antenna radar system antenna without installing an entire radar system.

Abstract: An air-launchable gliding sonobuoy store includes a canister enclosing an flatable membranous wing folded in a collapsed state with an electroacoustic system. After launching, the wing inflates and a steering mechanism controls the wing glide path by skewing the trailing edge thereof. Upon reaching the sea, the wing serves as a buoy with the electroacoustic system transducer depending therefrom.

Abstract: A method and apparatus for imaging underwater targets utilizing sidelooking onar. A sonar pulse consisting of a concatenated series of subpulses is transmitted. The echo return is match filtered against each of the subpulses to produce a series of range-doppler maps, each providing information in a different direction. The range-doppler maps are normalized, thresholded, and intersected, thereby yielding data points which describe the target outline. Information as to the target length, width and orientation can be computed from the target outline data.

Abstract: A bi-directionally corrugated sandwich construction for use in applications equiring high-strength, light-weight components is disclosed. The sandwich construction comprises first and second face sheets positioned essentially parallel to and spaced apart from each other and having a core therebetween. The core has two sets of corrugated strips which have planar peaks and troughs positioned at regular intervals. The strips of the first set are positioned parallel to and spaced apart from each other with the peaks and the troughs in phase with each other such that parallel rows of troughs are formed perpendicular to the strips. The strips of the second set are positioned parallel to each other with the peaks and troughs in phase with each other, and are positioned perpendicular to the first set of strips in the rows of troughs formed thereby.

Abstract: A respiratory system that is particularly suited to provide uncontaminated entilation and oxygen needs of an aircrew during the ground and flight operations is disclosed. The respiratory system has provisions to provide for a continuous flow of air or oxygen during the failure mode conditions of the ventilator and oxygen generating systems supplying the respiratory system so that the aircrew is always provided with at least a flow of uncontaminated breathing fluid under all such failure mode conditions.

Abstract: A corrosion-resistant coating which can be applied directly to a surface as self-priming corrosion-resistant topcoat comprising an alkyd resin binder and a combination of pigments consisting essentially of an aluminum triphosphate, zinc salts of benzoic acids, and an alkaline earth metal phosphate such as zinc-barium phosphate. In addition, the coating contains up to about 40 parts by weight of a titanium dioxide pigment, up to about 2.0 parts by weight of an oil-soluble surface active or wetting agent and up to about 40 parts by weight of at least one organic solvent.

Abstract: A real-time ship steering system provides steering of a survey ship along a rescribed thumb line track in accordance with a received point location on the thumb line and a received heading of the rhumb line. The system of the present invention requires an integrated navigation system, a track-keeping interface, and a ship autopilot to steer a ship. The computer of the navigation system integrates position data from continuous fixed radio and satellite positioning systems, inertial navigation systems, and dead reckon aids to develop the best present position. At prescribed equally spaced times, the best present position is used to compute the off-track distance of the ship. The off-track distance is used to develop proportional and integral heading corrections, which are applied to the autopilot by way of the track-keeping interface. The autopilot accepts the correction signal as a bias to the desired ground track heading, causing the ship to be steered toward the desired track.

Abstract: A convergent/divergent gas nozzle atomizes a liquid provided through a lid delivery tube having an aperture which is centered within a central gas conduit of an upstream mixing block connected to the nozzle. The aperture of the liquid delivery tube is located just upstream of a narrowed throat of the nozzle. The throat of the nozzle is dimensioned such that its inside diameter is equal to the outside diameter of the liquid injector tube. A spout is located at the discharge end of the nozzle which has an inside diameter equal to two times the inside diameter of the throat. This nozzle displays superior performance, providing an extremely fine mist having high momentum. This nozzle is particularly well-suited to fire extinguishment.

Abstract: A corrugated panel having a core between two faceplates where the core and aceplates are comprised of curable material and where the core is comprised of undulate strips that are disposed in parallel relation to each other. The strips define peaks and valleys connected by diagonally-extending segments that have non-planar cross-sections. The peaks and valleys in adjacent strips are 180 degrees out of phase with respect to each other. The faceplates and the strips are joined at the peaks and valleys.A method of making a corrugated panel assembly comprising the steps of providing upper and lower faceplates and a core of strips, all made from curable material. Mandrels and inserts are used to form the strips into alternately-arranged peaks and valleys that are interconnected by diagonal segments where the diagonally-extending segments have non-planar cross-sections. The strips are 180 degrees out of phase with respect to each other. The mandrels are replaced by granular particles and the assembly is cured.

Abstract: An anemometer having no moving parts and a sensing head with various emboents that improve the overall performance of the anemometer is disclosed. The sensing head of the anemometer generates an aerodynamic drag force when subjected to a dynamic pressure in the form of a moving fluid, such as wind. The aerodynamic drag force is translated to a deflectable column having a plurality of strain gauges thereon, each of which produces an electrical output voltage that is proportional to the wind speed. The sensing heads of the anemometer of the present invention reduced the velocity and directional error measurement parameters as well as reduce the angle of attack error.

Abstract: A flight simulator displays control choices on an out-the-window display allows a crew member to control it directly by making selections of displayed choices through a "point and click" control module accessible by the crew member while located in the crew station. The simulator can be controlled by either of two crew members and also by an operator at an instructor operator station outside the crew station.