Grumman Aerospace Corporation

Northrop Grumman Systems Corporation

Stanley M Reich

Carmine F Vasile

Donald R Lyons

Michael E Horn

Theodore W Hilgeman

Robert Silberstein

Daniel R Tufano

Michel Horn

Peter Shyprykevich

According to one embodiment of the invention, a method for locating a source of a signal includes detecting, at a plurality of locations, a near-field signal. The method also includes processing the near-field signal. The method further includes locating a source for the near-field signal based on the processed near-field signal detected at a plurality of locations.

System and method for locating a source of a signal

Absolute strain is measured by providing a coherent beam of light and separating the coherent beam of light into first and second beams which are in quadrature with one another and which have different polarization angles. The first and second beams are combined in a manner which maintains the different polarization angles thereof, so as to form a combined beam. The combined beam is then applied to a Fabry-Perot strain sensor so as to form a reflected combined beam. The reflected combined beam is then separated into first and second reflected beams having different polarization angles. The intensity of the first and second reflected beams is then sensed, so as to determine a change in the etalon length of the Fabry-Perot sensor. The change in etalon length is indicative of the absolute strain sensed.

Fiber optic Fabry-Perot sensor for measuring absolute strain

Fiber optic fabry-perot sensor for measuring absolute strain

A nonconducting, nonradiating remote communication system for use with medical research, diagnostic, and therapeutic instruments without disturbing the operation of those instruments, in which an image generator such as a CRT generates an image or stereo images to be viewed by a patient while the patient is being examined by the instrument. A fiber optic bundle relays the generated image to an eyeglass assembly worn by the patient. The eyeglass assembly comprises left and right image relay lens systems for relaying the images to the left and right eyes of the patient, and a mirror positioned between each relay lens system and the eye to reflect an image onto the eye. Each relay lens system can comprise a conventional relay lens system, or a graded index relay lens system, or a binary optic relay lens system. Each mirror can comprise a prism, or a pellicle mirror, a holographic mirror, or a binary optics mirror.

Nonconducting, nonradiating remote visual and audio communication systems

In order to control the direction of a magnetic field induced by a current sheet in a sheet conductor, relative to anomalies in a test sample, the current sheet is either rotated relative to the sheet conductor, by using either electrical or mechanical commutation of the current sheet, or the phases of plural independent current sheets in the sheet conductor are shifted relative to each other.

Apparatus and method for inducing eddy currents in a structure for

An apparatus for preventing, detecting, and predicting the formation and propagation of cracks in structural members. The apparatus includes a plurality of strain sensors integrally formed with a patch to be fixed to an area on the surface of a structural member. The patch operates to reduce stress levels in the patch-covered area for deterring the formation or propagation of a crack therein. The sensors monitor changes in the strain field in the patch-covered area for detecting crack formation and detection. The apparatus may also include a temperature-compensating strain sensor and a temperature sensor both integrally formed with the patch for detecting and predicting crack formation and propagation, respectively.

Intrumented patch for repair of fatigue damaged or sensitive structure

A method of magneto-optic eddy current imaging for detecting defects in a ferrous metal, non-ferrous metal, or non-metallic structure test object uses a sensor, magnetic field system, optical system, a video camera and a display. The method includes canceling undesired background of a two-dimensional magneto-optically generated image of a defect in the test object by dithering the image and processing signals from the video camera in compatibility with the dithering. The image is dithered once per frame of the camera, or at a sub-multiple of the frame of the camera, and the dithering may be accomplished manually or mechanically.

Magneto-optic eddy current imaging apparatus and method including

A fiber optic transmitter/receiver module used for controlling multi-axis beam steering of each individual radiating element in a phased array antenna and which is an integral part of a reconfigurable fiber optic corporate feed concept. In the receive mode of operation an incoming signal is captured, amplified and converted into the light domain by means of optical heterodyning. The relative phase and amplitude of the signal would be controlled by optically adjusting the amplitude and phase of a local oscillator. The local oscillator is sent to each fiber optic transmitter/receiver module. In the transmit mode of operation a signal for transmission which is in the light domain is down converted into the electromagnetic domain using optical mixing techniques. Once again, the relative phase and amplitude of the transmission signal would be controlled by the local oscillator. The beam steering capability is accomplished by configuring the local oscillator for each element of the antenna with a specific amplitude and phase.

Opto-electrical transmitter/receiver module

Prior art arrays of TR modules suffer from the disadvantage of requiring heavy and bulky waveguides or coaxial cables to provide controls therefore. In the present system, by using incoherent light to coherently synchronize the different TR modules of the array to produce a coherent phase array, the bulky waveguides and coaxial cables no longer are needed. To provide for the coherent synchronization of the phase array, oscillator and control signals are multiplexed onto different incoherent optical signals. The multiplexed optical signals are then summed and sent, via an optical fiber, to the TR modules of the array. At each of the TR modules, the oscillator signal and a corresponding control signal are separated from the summed optical signal and are used to weight the phase and amplitude of the radar signal to be transmitted from the TR module. When the properly synchronized and weighted modulated radar signal is sent from each of the TR modules, a coherently synchronized radar signal is produced.

Optical control of TR modules

An optical electronic multiplexing reflection sensor system for a plurality of Bragg sensors connected in series spaced relation in a plurality of single mode fiber optic cable buses. In each of the buses a unique address is provided each sensor function by wavelength selection. Each of a plurality of monochromators is coupled to a corresponding one of the buses and has a control connected to it for controlling the operation of the monochromator. A tunable laser source is coupled to each of the buses. A wavelength sweep generator is coupled to the laser source and provides outputs to the controls of the monochromators. Each of a plurality of photodetector receivers receives the output of a corresponding one of the monochromators and each has an output providing output signals indicating individual wavelengths of the Bragg sensors coupled to it. Each if a plurality of analog to digital converters is connected to the output of a corresponding one of the photodetector receivers. A backbone network connected to the analog to digital converters distributes and processes digitized data.

Optical electronic multiplexing reflection sensor system

To eliminate bulkiness associated with the conventional transmission of control signals to a phase array, and to overcome the precise requirements needed to coherently control a phase array in the prior art, the present invention uses incoherent light to provide optical synchronization of the phase array. For the system of the present invention, incoherent light, in the form of different optical signals having multiplexed thereon a local oscillator signal and a command signal including a plurality of control signals, are summed by a wavelength division multiplexer and sent, over an air path, to each TR module of the phase array. On receipt, each TR array separates from the summed optical signal the oscillator signal and a control signal which is recognizable and to be used only by that TR module. The separated oscillator signal is next fed to a mixer, for modulating a radar signal. The separated control signal provides weighting to the amplitude and phase of the modulated radar signal, relative to the other modulated radar signals from the other TR modules of the array. When all of the modulated radar signals are transmitted from the array, a coherently synchronized radar wave front is provided.

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Jericho, NY, United States of America

Stanley M Reich