Abstract: A weapons simulator for training a marksman on an anti-armor weapon. The pons simulator includes first and second broadcasting means for projecting on a reflective display screen a background scene, a visual target, and an infrared target spot in alignment with the visual target, and a two-axis laser spot positioning servo system for moving the aligned visual target and infrared target spot upon the reflective display screen. A matrix detector mounted within the weapon will sense the position of the infrared target spot upon the reflective display screen whenever the marksman fires the weapon, and then supply to a microprocessor computer digital information indicative of the position of the infrared target spot upon the reflective display screen. The microprocessor computer, in turn, processes the digital information so as to determine whether the marksman has scored a hit, a miss, or near miss upon the visual target.

Abstract: A discrete transducer array of a plurality of discrete transducer elements, o connected as to achieve a good array directivity pattern with as narrow a beam width as possible for a given side lobe level, or as low a side lobe level as possible for a given beam width, or the most favorable combination of the two. This is to be done with the restriction that there is a discrete array of, say 24, elements that must be shaded discretely, for example by using a series-parallel combination of the elements.

Abstract: Microstrip antenna systems having two ground planes spaced apart by a dietric substrate and radiating elements coplanar with one of the two ground planes, or sandwiched within the dielectric substrate separating the two ground planes adjacent a window in one of the ground planes. The two ground planes are shorted together in most instances, and the dual ground plane system provides a reduction in the leakage losses of transmission lines feeding and/or interconnecting the microstrip antenna radiating elements. The dual ground plane system also provides a reduction in coupling between arrayed radiation elements as well as an increase in bandwidth, in some instances.

Abstract: Microstrip antenna systems having two ground planes spaced apart by a dietric substrate and radiating elements coplanar with one of the two ground planes, or sandwiched within the dielectric substrate separating the two ground planes adjacent a window in one of the ground planes. The two ground planes are shorted together in most instances, and the dual ground plane system provides a reduction in the leakage losses of tranmission lines feeding and/or interconnecting the microstrip antenna radiating elements. The dual ground plane system also provides a reduction in coupling between arrayed radiation elements as well as an increase in bandwidth, in some instances.

Abstract: Improved method and apparatus for detecting anomalies beneath an area of earth's surface wherein an oscillator couples a current into two conductors laid parallel to each other to generate two magnetic fields in the earth beneath the area. The magnetic field is measured along a line midway between the two horizontal conductors to detect for an increase in the measured field which is an indication of the presence of an anomaly.

Abstract: A system for locking a missile seeker to a desired target signal while the issile is in flight and approaching the target. The target is detected and tracked by a remote radar. The missile is launched and utilizes an inertial mid-course guidance to guide it in the general direction of the target. A data link is established between the remote radar and the missle seeker. When the missile is sufficiently close to the target its active radar is turned on and target information is transmitted via the data link to the remote radar or tracking station. The remote tracking station transmits back to the missile information for correcting its tracking course and provides information which effects missile seeker lock-on of the target of interest and will cause the missile seeker to continue to track the target until impact.

Abstract: Fibers, particularly optical fibers, are tested for determining their tene strength in expected environments. A pair of sheaves, on journaled and the other fixed receive a looped length of fiber and are placed within a cylindrical shell which is filled with an expected environmental medium, such as seawater. The sheaves are pulled apart subjecting the fiber to tensile loading and a strain gauge provides responsive read-outs so that the fiber's fatigue strength can be determined. The size of the sheaves and adhesively securing the loose ends of the fiber prevents the generation of any spurious pinching torsional stresses. Placing the fiber in the environmental fluid allows a monitoring of the effects of the fluid on the fiber's cladding and core so that the strength limits of the fiber are accurately determined under simulated operational conditions.

Abstract: A system for interconnecting and switching teletypewriter or digital data gnals when transmitted over any of the four universally accepted standard signal loops. The system incorporates a novel triple loop arrangement; an "IN" loop connected to a signal source, an "INTERNAL" loop to provide switching and an "OUT" loop connected to the signal destination. Each "IN" loop or "OUT" loop together with half of its associated "INTERNAL" loop is implemented in a single printed circuit card. The system can incorporate any number of "IN" and "OUT" loops and the associated "INTERNAL" loops.

Abstract: An antenna system having a multiple of antenna feeds to drive a microwave ns, composed primarily of a Luneberg lens and a metallic ground plane upon which are mounted three antenna feeds and a shorted stub (or four bent-stub coaxial feeds). The antenna system uses a common aperture to provide antenna performance for the three separate feeds, conserving space that would normally be required for three separate high gain antennas.

Abstract: A bearing pad for slidably supporting a relatively movable load applying ber. The pad comprises a face member swingably mounted on a base member and having a bearing surface laterally offset toward the leading edge from the nadir of the base member and facing the movable member whereby the load normal to the bearing surface and frictional drag across the bearing surface both act to cause the face member to swing arcuately in the direction of movement of the moving member thereby tilting the bearing surface for trapping a wedged shaped film of lubricant between the bearing surface and the movable member.

Abstract: An improvement for a sonar is provided wherein the improvement includes a ne array of N listening transducer elements, each listening element being capable of receiving an acoustic signal and outputting a corresponding electrical signal. A plurality of beamformers is provided wherein each beamformer has an input and an output, the input of each beamformer receiving the output from each listening element. A switching device is interconnected between the listening elements and the beamformers for alternately switching the outputs of the listening elements to each beamformer between two modes, one mode being a predetermined order and the other mode being an inversion of the predetermined order. With this arrangement only half the normal number of beamformers is required, thereby significantly reducing the weight and size of the sonar.

Abstract: A double layer inflatable bag for protecting a blade of an aircraft. The includes a puncture proof outer layer and a flexible inner layer joined together at the extreme ends to form an elongated bag. Means for inflating various sections of the space in between two layers are provided. The bag is put on over the blade and is inflated. Inner layer of the bag is in contact with the blade to keep it in position and the outer layer thereof protects the blade from damage.

Abstract: An electro-optical system for performing the computation of the radar ambiguity function or other similar mathematical function using the parallel processing capability of optical systems including a photo-responsive, real-time programmable mask for storing a set of sample values {s.sub.p }. A light source is positioned to illuminate the mask and have its intensity modulated as a function of the sample values {s.sub.p }. The image from the programmable mask is transferred to a CCD photo-sensor array that is clocked in synchronism with the light pulse outputs of the light emitting diode to give rise to electro-optical products which are integrated in the CCD structure to yield the ambiguity or other similar mathematical function.

Abstract: A device for connecting plural oscillators to a single output port without he use of power dividers, switches or multiplexing filters. The plural oscillators produce multiple frequencies with only one oscillator operating at a given time. The oscillators are mounted in shunt waveguide cavities along a central waveguide manifold at distances from the central waveguide manifold and waveguide end so as not to affect the operating oscillator.

Abstract: A constant amplitude, variable frequency, synchronized, linear ramp generr is disclosed for generating a sawtooth waveform signal, whose amplitude is independent of frequency. A capacitor is charged by a voltage controlled current source, which is responsive to a feedback control signal provided by an integrator; and subsequently discharged by a clamp, which is responsive to a trigger pulse signal, so as to establish a ramp voltage across the capacitor. The ramp voltage, which appears at the output of the linear ramp generator as the sawtooth waveform signal, in turn allows a television system to operate at various line rates.

Abstract: Apparatus for indicating the level of the electrolyte in a battery cell. A three-electrode sensor probe having the electrodes partially embedded in an electrically insulating housing suspended in the electrolyte so that a portion of the probe is immersed in the electrolyte. The electrolyte provides the only conduction path between the electrodes so that the resistance between the electrodes varies according to the level of the electrolyte. An AC or pulsed DC sensing signal is applied between two of the electrodes and an output signal related to the level of the electrolyte is produced. A polarizing current is applied to the other electrode to prevent the buildup of surface contamination on the two sensing electrodes due to the sensing signal.

Abstract: A pulse repetition interval generator with stagger circuit for providing a ulse repetition interval signal. The pulse repetition interval generator can be used with a device for generating simulated antenna scan patterns of conventional search radar antennas and comprises a source of clock pulses, a counter circuit, a repetition interval setting means, pulse generator means and a pulse width determining means.

Abstract: Control circuitry for producing signals to control motors which propel a ile platform for a standing paraplegic. Logic circuits connect a 3-axis joy stick controller to four permanent magnet DC motors mounted on the platform such that the platform follows in the direction of the displacement of the joy stick. The joy stick outputs are taken as inputs to several differential amplifiers. Each of a plurality of velocity servo amplifiers receives one input signal from the differential amplifier output and another from a tachometer feedback signal derived from each motor. Comparators receive the velocity servo amplifier outputs as well as a triangular wave input. Each comparator comprises a pulse width modulator which generates pulse outputs whose duty cycle is a function of the voltage inputs to each comparator. The comparator outputs then control motor rotation such that the platform moves in the direction of displacement of the joy stick.

Abstract: A hydrophone deployment apparatus is provided for an underwater vehicle, rein the apparatus includes an annular drum releasably mounted about the tail portion of the vehicle. A plurality of arms are pivotally connected to the aft portion of the drum and are capable of swinging from forward positions flush with the vehicle to aft positions behind the drum. A device is provided for enabling retention and selective releasing of the arms from the forward flush positions. A hydrophone is releasably mounted on the inside of one of the arms, and a cable is connected between the hydrophone and the vehicle with an intermediate portion wound on the drum. With this arrangement a release of the arms during travel of the vehicle will cause the drum to be released and the vehicle will swim away from the drum pulling the cable until it is completely off the drum, at which time the hydrophone is pulled from its mounting in the arm. At this time the drum is jettisoned and the hydrophone becomes operational.

Abstract: A mechanically actuated, piezoelectrically powered, fiber optic connected ght valve (shutter) utilized as a sensor to detect mechanical motion (pressure) or displacement. A piezoelectric element responds to pressure to generate an electrical signal which is applied to a Kerr cell containing nitrobenzene; the signal in turn renders the nitrobenzene transparent and light via fiber optic means is allowed to pass through the Kerr cell and return to the light source location for sensing.