Abstract: A method for detecting an object in a body of water by generating a plurality of signals and applying each signal to a separate submerged sonar node that is a part of an array of sonar nodes.

Abstract: A novel aspect to the invention is a structural arrangement to widen the Fabry-Perot gap beyond a 100-micron LC thickness. The widening permits greatly enhanced spectral discrimination (i.e. many more WDM channels) across the device response range, which is expanded to ITU standards by use of the twin etalon configuration. A liquid crystal optical multiplexer according to the present invention is a two-etalon Fabry-Perot laser etched into many (>100) sub-etalons in a rectangular array. Each sub-etalon is independently tunable and can be coupled to a distinct fiber. Any single sub-etalon or random combination of sub-etalons is free to be tuned to a particular wavelength corresponding to one of the input channels. This allows for any combination of signals (i.e digital video, data and voice) in a signal broadband channel to be switched to any of several receivers. Wavelength division multiplexing (WDM) is used to combine or separate individual types of signals from a single fiber.

Abstract: A novel aspect of the invention is a structural arrangement to widen a Fabry-Perot gap beyond a 100-micron LC thickness. The widening permits greatly enhanced spectral discrimination (i.e. many more WDM channels) across the device response range, which is expanded to ITU standards by use of a twin etalon configuration. A liquid crystal optical multiplexer according to the present invention is a two-etalon Fabry-Perot laser etched into many (>100) sub-etalons in a rectangular array. Each sub-etalon is independently tunable and can be coupled to a distinct fiber. Any single sub-etalon or random combination of sub-etalons is free to be tuned to a particular wavelength corresponding to one of the input channels. This allows for any combination of signals (i.e. digital video, data and voice) in a signal broadband channel to be switched to any of several receivers. Wavelength division multiplexing (WDM) is used to combine or separate individual types of signals from a single fiber.

Abstract: An LC optical multiplexer according to the present invention is a two-etalon Fabry-Perot laser etched into many (>100) sub-etalons in a rectangular array. Each sub-etalon is independently tunable and can be coupled to a distinct fiber. Any single sub-etalon or random combination of sub-etalons is free to be tuned to a particular wavelength corresponding to one of the input channels. This allows for any combination of signals (i.e digital video, data and voice) in a signal broadband channel to be switched to any of several receivers. Wavelength division multiplexing (WDM) is used to combine or separate individual types of signals from a single fiber. Phase-matching coatings are used on the materials within the Fabry-Perot gap, thereby enhancing transmission performance of the WDM device. Mechanical techniques are used to widen the Fabry-Perot gap beyond a 100-micron LC thickness. The widening permits greatly enhanced spectral discrimination (i.e.

Abstract: A non-invasive elastic wave fluid level sensing system for use in sludge laden environments, including transmitting and receiving transducers mounted on an outer face of a wall of a container for a fluid and along a propagation path for an elastic wave transmitted through the wall of the container wherein the elastic wave has a frequency of less than 5 kHz, more preferably less than about 2 kHz, and most preferably less than 1 kHz. A signal processor determines a change in a characteristic of the elastic wave between when a fluid is present in the container in the region of the propagation path and when a fluid is not present in the container in the region of the propagation path. One embodiment utilizes multiple horizontally oriented transmitting and receiving transducer pairs to detect levels of the fluid in the container.

Abstract: A deployable buoy having a nose cone and a tail section interconnected by a housing. The buoy comprises an outer shell and a canister with the outer shell axially moveable relative to the canister. An expansion chamber is provided between the outer shell and canister to produce and increase the axial length of the buoy and thereby increase the buoyancy of the buoy from a low buoyancy to a greater buoyancy and to orient and maintain the buoy in a substantially vertical orientation. The buoy is provided with a hot fluid generation source to melt a layer of ice and a nose cone ejection system to expose an antenna for the transmission of data to the central processing system.

Abstract: A hydrophone arrangement, housed within a dome shaped concrete and steel bunker, to accurately establish a bearing of a target object while diminishing potential displacement of the hydrophone arrangement from an initial installed position. A plurality of hydrophones are centrally positioned within the bunker and equally spaced about a periphery of a steel cylindrical member so that each hydrophone receives acoustic energy in a time delay manner with respect to the other adjacent hydrophones so that a bearing determination may be made from information received by a single stand alone bunker. An acoustic horn may also be provided to focus the acoustic energy towards the hydrophones to improve the signal-to-noise ratios and provide control of the phase of the acoustic energy as the energy is received by the hydrophones.

Abstract: A sensing apparatus, for use in adverse conditions comprising a housing having an aperture formed therein. A generally spherically shaped housing, which is larger in size than the aperture, partially extends through the aperture. The generally spherically shaped housing supports a desired sensor and is supported for rotation about an axis of rotation. A drive mechanism is provided for rotating the generally spherically shaped housing to and fro about its rotational axis from a use position, in which the sensor is positioned outside the housing to obtain sensor measurements, to a retracted position in which the sensor is completely accommodated within the housing and sheltered from the elements. A peripheral scraping ring is mounted circumferentially about the aperture in close proximity to an exterior surface of the generally spherically shaped housing but spaced therefrom.