Abstract: A computerized machine (a) determines temporal and spatial confidence intervals for each one of plural sonic events, (b) classifies pairings among the sonic events as either comparable or non-comparable, and (c) estimates a minimum number of sonic sources, some of which are in motion, that could have produced or generated the sonic events. Sonic event times and positions are characterized by corresponding temporal and spatial confidence intervals. A pairing of sonic events is classified as comparable only when that pairing meets one or more preselected constraints, some of which depend on the temporal and spatial confidence intervals. The estimated minimum number of sonic sources is equal to the total number of sonic events minus the cardinality of a maximum matching of a bipartite graph derived from the classifications of the pairings and a chronological ordering of the set of sonic events.

Abstract: A computerized machine (a) determines temporal and spatial statistical characterizations for each one of plural sonic events, (b) classifies certain pairings among the sonic events as comparable, and (c) estimates a minimum number of sonic sources, some of which are in motion, that could have generated the sonic events. Sonic event times and positions can be characterized by corresponding temporal and spatial confidence intervals. A pairing of sonic events is classified as comparable only when that pairing meets one or more preselected constraints, some of which depend on the temporal and spatial statistical characterizations. The estimated minimum number of sonic sources is equal to the number of sonic events in a longest antichain within a chronological ordering of the set of sonic events. An antichain comprises a subset of the sonic events for which no pairing of sonic events of that subset is a comparable pairing.

Abstract: A method implemented using a programmed computerized machine includes using an estimated uncorrected time-difference-of-arrival (TDOA) for a first signal at first and second sensors, located at first and second sensor locations and coupled to first and second clocks, to calculate a first estimated clock synchronization error (CSE) range that extends (i) from an estimated minimum true TDOA between the sensor locations minus an estimated maximum uncorrected TDOA, (ii) to an estimated maximum true TDOA between the sensor locations minus an estimated minimum uncorrected TDOA. Additional estimated CSE ranges based on additional signals can be used to calculate an estimated cumulative CSE range. A first or cumulative estimated CSE range can be used for calculations with respect to time-dependent signals arriving at one or both sensors, or for adjusting one or both clocks.

Abstract: Multistatic active coherent sonar systems and methods include reception by floating receiver sonobuoys of acoustic signals emitted by floating source sonobuoys, by both direct propagation from the source sonobuoys and reflection or scattering from a target object. Subsequent calculations based at least in part on those signals can be employed to estimate relative or absolute positions or velocities of the target object and the source and receiver sonobuoys. The estimated relative velocities and positions can be calculated without relying on GPS or other extrinsic positioning signals acquired for each sonobuoy after its deployment. Acoustic signals emitted by a stationary source on the seabed, received by a stationary receiver on the seabed, or reflected/scattered from a bathymetric feature, can be employed to estimate absolute or relative positions or velocities of the target object and the source and receiver sonobuoys.

Abstract: A smart fluid application system and method for the delivery of a fluid to a discreet location is disclosed in the present application. The system and method utilize a rigidly affixed port block with multiple discharge ports, where each port has at least two apertures, all of which are positioned and designed to dispense a fluid only to a pre-determined location. At least one sensor detects an event and directs the release of fluid through a specific port and ceases the release when the event is ended. Such a system and method may be used anywhere a precise application of fluid is required.

Abstract: A smart fluid application nozzle consisting of an optical based event locating system, a multi-port nozzle block, and a port switching mechanism is disclosed by the present application. The smart nozzle utilizes a unique arrangement of discharge ports, allowing the angle of the discharge agent to be controlled without moving the nozzle housing. Multiple ports are activated per event to create a uniform fluid distribution within the discharging jet while controlling the discharge angle, which cannot be achieved through a single port discharge. Upon receiving a detection signal, the event locating system determines the spatial location of the event region and activates the appropriate discharge ports, thereby directing agent toward the event zone and applying fluid while minimizing damage to nearby areas. The use of the system may be used wherever the precise directed application of as fluid is desired including, fire suppression.

Abstract: The structure for the reduction of noise occurring when a fluid flow passes over a surface is disclosed by the present application. The structure comprises a surface with a top face that is roughly parallel to the flow wherein the face has an array of multiple separate and discreet cavities inset into the surface. Each cavity may be tuned to mitigate the noise of a specific frequency of the flow by altering the size, shape, position, angle in relation to the flow and ratios of depth, width, and length of the cavity. The cavities may be divided by partitions into sub-cavities of differing sizes, shapes and positions to mitigate noise as well. The structures may be applied to any application where a flow exists over a surface including, but not limited to, aerospace, automotive, naval and electronics. The structure may be flat, curved, tubular or any other shape subject to fluid flow.

Abstract: Robust methods are developed to provide bounds and probability distributions for the locations of objects as well as for associated variables that affect the accuracy of the location such as the positions of stations, the measurements, and errors in the speed of signal propagation. Realistic prior probability distributions of pertinent variables are permitted for the locations of stations, the speed of signal propagation, and errors in measurements. Bounds and probability distributions can be obtained without making any assumption of linearity. The sequential methods used for location are applicable in other applications in which a function of the probability distribution is desired for variables that are related to measurements.

Abstract: Robust methods are developed to provide bounds and probability distributions for the locations of objects as well as for associated variables that affect the accuracy of the location such as the positions of stations, the measurements, and errors in the speed of signal propagation. Realistic prior probability distributions of pertinent variables are permitted for the locations of stations, the speed of signal propagation, and errors in measurements. Bounds and probability distributions can be obtained without making any assumption of linearity. The sequential methods used for location are applicable in other applications in which a function of the probability distribution is desired for variables that are related to measurements.

Abstract: A method of localizing signals utilizing auto-correlation functions and cross correlation functions includes: collecting data at a plurality of input channels; filtering the data collected from the plurality of input channels in order to identify a primary signal; identifying at least two lags and at least one reference lag in a function of the data; and estimating relative travel times of the data.

Abstract: An apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam of gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite, releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: The invention relates to an apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam of gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite, releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: The invention relates to an apparatus and method for detecting the presence of an element of interest within an object. The object is positioned where a beam gamma rays of the required energy are directed to be scattered by the element of interest. The gamma rays are provided by excited atoms of the element of interest. The excited atoms result from the reaction of hydrogen or heavier ions and a suitable target. The excited atoms deexcite releasing gamma rays which are scattered by the element of interest within the object. The scattered gamma rays are detected, output signals are produced, processed and analyzed to determine the amount of the element of interest within the object. A preferred embodiment relates to the detection of nitrogen-based explosives in luggage.

Abstract: An apparatus and method for scanning an object for nitrogen for detecting the presence of explosives in luggage, parcels and the like. The object is placed in a cavity in which a thermal neutron flux is produced by introducing fast neutrons in the presence of a nuclear moderating material. A reaction between the thermal neutrons and the nitrogen contained in the object causes gamma rays to be emitted which are detected and transmitted to processing electronics to determine the concentration and position of nitrogen in the object. Thermal neutrons sensors are located within the cavity to monitor the amount of thermal neutrons and adjust the thermal neutron flux within the cavity in order to maintain an optimal thermal neutron flux density within the cavity. The adjustment may be effectuated by adjusting the accelerating potential of a neutron accelerator or by adjusting the position of a neutron moderator for use with an isotopic neutron source.

Abstract: A method and apparatus for imaging the concentration of paramagnetic species inside a sample is disclosed wherein a sample is placed inside an NMR imager and an additional microwave field is introduced. A microwave field is chosen in such a way that there is a simultaneous resonance of nuclear spins (protons) and electrons in the same main magnetic field. The microwave signal is modulated which provides a modulation transfer to the intensity of the NMR signal. The modulation is extracted from the NMR signal to produce an image representative of the local electron spin resonance (ESR) and thereby the concentration of paramagnetic species in the sample. In addition, electrical activity of the brain can be detected and measured by measuring the broadening of the width of NMR spectral lines. A discharging neuron in the brain introduces an inhomogeneity in the magnetic field which reveals itself as a broadening of resonance lines which can be measured to determine the neuron discharge current flux.