An acoustic vector sensor and a method of detecting an acoustic vector are described. An object suspended in the fluid medium by a non-contact support structure. The object and the non-contact support structure are configured so that the object moves in response to any disturbance of the fluid by an acoustic wave; The non-contact support structure of the object comprises a plurality of solenoids that each produce a magnetic field in a fluid medium. A measurement measures movement of the object. A processing device determines an acoustic intensity vector of the acoustic wave based on the measured movement of the object.

An acoustic vector sensor and a method of detecting an acoustic vector are described. An object suspended in the fluid medium by a non-contact support structure. The object and the non-contact support structure are configured so that the object moves in response to any disturbance of the fluid by an acoustic wave; The non-contact support structure of the object comprises a plurality of solenoids that each produce a magnetic field in a fluid medium. A measurement measures movement of the object. A processing device determines an acoustic intensity vector of the acoustic wave based on the measured movement of the object.

A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

An electronic beacon placed stationary in a known location. The beacon includes a map, stored therein, pertaining to a covered area. The map includes coordinates of the known location with reference to the map. The electronic beacon is configured to transmit at least a navigational signal. The electronic beacon has a radio transmitter to communicate the map to at least one moving device in the covered area.

Systems and methods are provided for sensing acoustic signals using a floating base vector sensor. A vector sensor according to an embodiment of the present disclosure can be used to detect and characterize low frequency sound wave(s) in a viscous medium (e.g., air, water, etc.) by detecting a periodic motion of the media particles associated with the sound wave(s). The orientation of the particle velocity deduced from such measurements can provide information regarding the wave vector of the sound wave(s), can define the direction of arrival (DOA) for the acoustic signal, and can assist locating the source of the sound of interest.

Systems and methods are provided for sensing acoustic signals using a floating base vector sensor. A vector sensor according to an embodiment of the present disclosure can be used to detect and characterize low frequency sound wave(s) in a viscous medium (e.g., air, water, etc.) by detecting a periodic motion of the media particles associated with the sound wave(s). The orientation of the particle velocity deduced from such measurements can provide information regarding the wave vector of the sound wave(s), can define the direction of arrival (DOA) for the acoustic signal, and can assist locating the source of the sound of interest.

An apparatus comprising at least one first microphone (10) which is movably arranged, at least one second stationary microphone (11) and at least one sensor (16) is described. The microphones can capture the sound waves emitted by acoustic sources, and the sensor can capture spatial coordinates of the first microphone. A corresponding method and a system having the apparatus mentioned are also described.

A method for testing a structure includes steps of: identifying a three-dimensional position of a surface of the structure relative to a reference frame; transmitting laser light from an output of a transmitter onto the surface of the structure to form ultrasonic waves in the structure and to detect a response to the ultrasonic waves; based on the three-dimensional position of the surface, moving the laser light over the structure along a scan path so that the output of the transmitter is located at a constant offset distance from the surface and that the laser light, transmitted from the output of the transmitter, is directed onto the surface at a constant angle of projection; and based on the response to the ultrasonic waves, determining whether an inconsistency is present in the structure.

A method for testing a structure includes steps of: identifying a three-dimensional position of a surface of the structure relative to a reference frame; transmitting laser light from an output of a transmitter onto the surface of the structure to form ultrasonic waves in the structure and to detect a response to the ultrasonic waves; based on the three-dimensional position of the surface, moving the laser light over the structure along a scan path so that the output of the transmitter is located at a constant offset distance from the surface and that the laser light, transmitted from the output of the transmitter, is directed onto the surface at a constant angle of projection; and based on the response to the ultrasonic waves, determining whether an inconsistency is present in the structure.