Abstract: Embodiments of the present invention beneficially provide an ultrasound communication system and methods of ultrasound communication for diagnostics and prognostics of structures. For example, ultrasound transmitters are connected to a metal or composite structure and modulated to produce Lamb waves that travel to an ultrasound receiver. The ultrasound transmitters can use frequency-hopped signals to digitally encode transducer information among different transmitters. The transmitters can be operated asynchronously. The receiver can use a channel equalizer to reduce the effects of signal multipath and a decoder to decode the transducer information from the ultrasound transmitters.

Abstract: A radar system having a processor, a waveform generator, a plurality of antenna interfaces, a set of first antennas configured to transmit a waveform, and a set of second antennas configured to receive a reflected waveform is disclosed. The waveform generator and antenna interfaces are in control and signal communication with the processor, each of the first antennas are in signal communication with one of each antenna interface, and each of the second antennas are in signal communication with one of each antenna interface. The waveform generator is in control and signal communication with each antenna interface, and is configurable to generate a waveform conforming to at least two ISM bands. Each first antenna is configured to transmit a circularly polarized electromagnetic waveform, and each second antenna is configured to receive a reflected circularly polarized electromagnetic waveform complementary to the first antennas.

Abstract: A system and method for establishing communications in a power plant comprises a power generation system having an interface for establishing wireless communication, at least one power plant auxiliary system having an interface for enabling wireless communication, and a wireless communications link, having at least two redundant wireless communications channels, established between the power generation system and the power plant auxiliary system. The two redundant wireless communications channels may be two redundant wireless radio frequency channels. The communications link may be established utilizing a network communications controller which wirelessly communicates with the power generation system and the power plant auxiliary system. One or more of the power plant auxiliary systems may communicate with the network communications controller through a repeater.

Abstract: A mode of communication for asset tracking units involves communication between a central station and the individual tracking units, usually through a satellite link. This mode is the primary communication link for tracking the assets. A second mode is the local area network (LAN) or "mutter" mode, in which a subset of tracking units communicate with each other in a mobile LAN. This mode is used as the secondary communication mechanism to conserve power, since mutter mode communication requires much less energy for local communication between the tracking units as opposed to direct satellite communication with the central station. In addition, mutter mode leads to increased reliability of the asset tracking system by enabling tracking of units which have batteries too weak to support communication with the central station, but strong enough to support communication in mutter mode.

Abstract: A fiber optic probe system includes a fiber optic probe and a carrier cable coupled to the probe. The carrier cable includes an excitation fiber for receiving excitation light and supplying a portion of the excitation light to the fiber optic probe, a return fiber for receiving detected light from the probe, and a directional coupler coupling the excitation fiber with the return fiber. The directional coupler is situated near an end of the carrier cable which is closest to the probe. A plurality of these fiber optic probes can be multiplexed using a plurality of carrier cables, each cable having a respective excitation fiber for receiving excitation light and supplying the excitation light to a respective one of the plurality of fiber optic probes.

Abstract: A mobile tracking unit capable of operating in a power-starved environment for a vehicle tracking system includes a navigation set for generating data corresponding to a respective vehicle position. The navigation set is periodically energized at a selected activation rate F.sub.G while the vehicle is moving to generate the vehicle position data. The tracking unit includes an electromagnetic emitter which is capable of transmitting the vehicle position data and which is periodically energized at a selected activation rate F.sub.EM while the vehicle is moving to transmit at least the vehicle position data. A motion sensor is employed for generating data indicative of vehicle motion. A tracking unit controller receives the vehicle motion data and controls the navigation set and the emitter based upon the vehicle motion data so that when the vehicle is stationary each of activation rates F.sub.G and F.sub.

Abstract: An optical detection system includes an array of photodetectors, each of which is positioned for receiving light and converting the light into an electrical signal. A plurality of high pass filters is positioned with each one of the high pass filters electrically coupled to a respective photodetector for passing a portion of a respective electrical signal having frequency components at least as high as the high pass filter cutoff frequency. In one embodiment, each one of the filters comprises a capacitance coupled to the photodetector and a depletion mode FET with shorted gate-to-source terminals coupled between the photodetector and a bias voltage source.

Abstract: In an array of charge injection device (CID) detectors, integer amplification is incorporated into each respective detector of the array. The amplifier for each CID detector in the array performs multiple nondestructive readouts. This provides a gain of N amplification of the signal charge in that detector wherein the signal charge is accurately replicated in a separate charge storage well defined by a magnitude capacitor coupled to the detector. Thus, at the end of the readout process, this separate well contains charge equal to N times the signal charge, N being the number of nondestructive readout cycles in the readout process.

Abstract: Coherent light is projected through a scattering medium. The light emerging from the medium is a superposition of a multitude of scattered wavelets, each of which represents a specific scattering path. These wavelets are projected onto a diffuse reflecting surface (the viewing plane of a two-dimensional photodetector array) where they interfere with each other, giving rise to a speckle pattern. By introducing a focused ultrasound pulse into the medium, the position of the scatterers are changed at a known location (probe region) in the medium, and this causes a change in the speckle pattern. By comparing speckle images before and after the scatterers are moved, the light absorption properties of the probe region can be measured even though multiple scattering interferes with direct imaging of the region.

Abstract: Respective processors for pairs of photodetecting elements are included in an imager used for sensing hologram fringe patterns in an optical interferometer. These processors remove the direct-current pedestal from in-phase and quadrature-phase field images, then perform partial correlations of the resulting field images on a pixel-by-pixel basis, and then sum the partial correlations to complete the image correlation process and to provide imager output signal or the basis therefor. This localized processing greatly reduces the number of samples that have to be brought out of the imager each frame when the imager is used in an optical interferometer to detect phase modulation in an optical signal, allowing for increased frame rates in accordance with a further aspect of the invention. Image correlation is done according to a novel algorithm that avoids actually having to multiply together correspondingly located pixels in each pair of successive fields forming a successive non-overlapping frame.

Abstract: An apparatus for introducing test gas commonly containing an inert gas and carbon monoxide to a patient through a mouthpiece which, in turn, is attached to a sample chamber within which are arranged sensors enabling measuring of carbon monoxide, carbon dioxide, an inert gas or other gases. Valving permits the test gas to be inhaled by the patient and then exhaled into the chamber. Further valving at the outlet of the chamber permits evacuation through a gas volume measuring device after measurements within the chamber have been completed. Sample chambers may be of various shapes but preferred forms are essentially linear or closed loop arrangements.

Abstract: A method for determining the average gray value of a plurality of regions within a digitized electronic video image and for determining the color of the region from the average gray value. Initial image segmentation is accomplished by thresholding a multibit digital value into a one bit black and white representation of a picture element of the region. The gray values of the picture elements within either a black or a white region can then be analyzed to determine the average gray value by constructing a histogram of each region and eliminating from the histogram the picture elements not associated with the actual color or shading of the region of interest. The remaining picture elements are averaged to obtain the average gray value for the region.

Abstract: Method and apparatus is disclosed for automatically processing visual images electronically so as to permit intelligent machine analysis of the image content. A special distributed logic system architecture facilitates rapid real time image analysis and the production of reaction control signals in a high speed production line environment, for example. Dedicated decision logic is employed to determine in but a single micro-instruction cycle whether a detected corner point of the image should be linked to another already linked chain of such corner points so as to define part of a closed edge contour of the image under examination. This ability to so rapidly classify encoded corner points as either belonging or not belonging to a given set of such corner points which describe a closed edge contour is quite useful in achieving rapid real time image analysis capability.

Abstract: Method and apparatus is disclosed for automatically processing visual images electronically so as to permit intelligent machine analysis of the image content. A special distributed logic system architecture facilitates rapid real time image analysis and the production of reaction control signals in a high speed production line environment, for example. Dedicated decision logic is employed to determine in but a single microinstruction cycle whether a detected corner point of the image should be linked to another already linked chain of such corner points so as to define part of a closed edge contour of the image under examination. This ability to so rapidly classify encoded corner points as either belonging or not belonging to a given set of such corner points which describe a closed edge contour is quite useful in achieving rapid real time image analysis capability.

Abstract: A weighing scale with an electrical output includes a mechanical-to-electrical signal transducer which has a zero weight signal value which may vary in response to ambient conditions. The scale includes a fast acting switch operable to provide a switching function in response to the initiation of the placement of a weight upon the scale and a weight registering circuit operable in response to the switching function to register and store a zero weight signal before the signal transducer begins sensing the weight. The weight registering circuit is then operable to register the difference between the zero weight signal value and the ultimate signal from the transducer as the true weight.

Abstract: An array of charge storage devices each including a pair of closely coupled conductor-insulator-semiconductor cells, one a row line connected cell and the other a column line connected cell, is provided on a common semiconductor substrate. Readout of the charges stored in each row of devices of one set of alternate rows is accomplished by transferring the charge in each of the devices of each of the rows in one direction between the row line connected cell and the column line connected cell of a device in sequence and sensing the resultant current flow in each of the row lines of the set. Readout of the charges in each row of devices of the other set of alternate rows is accomplished by transferring the charge in each of the devices of each of the rows in the other direction between the row line connected cell and the column line connected cell of a device in sequence and sensing the resultant current flow in each of the row lines of the set.