A two-scale array for detecting wind noise signals and acoustic signals includes a plurality of subarrays each including a plurality of microphones. The subarrays are spaced apart from one another such that the subarrays are configured to detect acoustic signals, and the plurality of microphones in each subarray are located close enough to one another such that wind noise signals are substantially correlated between the microphones in each subarray.

A method as well as a device for recording precipitation events are described. Here, sound transducers for emitting and receiving ultrasonic signals are provided, which, de-pending on a property of these ultrasonic signals, generate a measurement signal, which is evaluated to determine at least one atmospheric parameter. The solution described is characterized by the fact that a precipitation event is detected on the basis of the evaluation of the measurement signals generated by the sound transducers.

Because of the increase of the obesity related diseases, it is desirable to be able to detect a fatty liver and quantify the content in fat for the fatty liver. Known methods are biopsy and magnetic resonance imaging. However, biopsy is an invasive method and magnetic resonance imaging is a complicated method to carry out. The inventors propose a new ultrasonic method, which is more compliant with a regular control of the content in fat for the fatty liver for a subject. This method notably relies on a smart exploitation of the coherence properties of ultrasound pulses applied to the liver. This method has already been validated on sane subjects as providing accurate measurements, notably for fat content.

A sensor device includes: a first sensor group (13) in which a plurality of first vibration sensors for detecting vibration acceleration in one direction with respect to an object to be detected are arranged to face the same direction; a phase difference calculation unit (220) which, based on a plurality of first signals indicating the vibration acceleration detected by each of the plurality of first vibration sensors included in the first sensor group (13), calculates a first phase difference indicating the phase difference between the plurality of first signals; and an acceleration calculation unit (230) which, using the first phase difference and the plurality of first signals, calculates vibration acceleration in a first direction perpendicular to a surface on which the plurality of first vibration sensors are arranged, and vibration acceleration in a second direction parallel to the surface on which the plurality of first vibration sensors are arranged.

A sensor device includes: a first sensor group (13) in which a plurality of first vibration sensors for detecting vibration acceleration in one direction with respect to an object to be detected are arranged to face the same direction; a phase difference calculation unit (220) which, based on a plurality of first signals indicating the vibration acceleration detected by each of the plurality of first vibration sensors included in the first sensor group (13), calculates a first phase difference indicating the phase difference between the plurality of first signals; and an acceleration calculation unit (230) which, using the first phase difference and the plurality of first signals, calculates vibration acceleration in a first direction perpendicular to a surface on which the plurality of first vibration sensors are arranged, and vibration acceleration in a second direction parallel to the surface on which the plurality of first vibration sensors are arranged.

Methods for determining separate velocity components of an acoustic wavefield that are incident on a distributed fiber optic sensor are disclosed. A fiber optic sensor includes fiber that is spatially distributed in non-parallel planes of a three-dimensional volume having three orthogonal axes. The fiber includes a first fiber pattern that is spatially distributed within a first plane of the three-dimensional volume, and a second fiber pattern that is spatially distributed within a second plane of the volume. The fiber patterns are interrogated separately by a distributed fiber optic interrogation system. The individual responses from each pattern are combined and processed to determine separate velocity components of the acoustic wavefield relative to the orthogonal axes of the three-dimensional volume.

Methods for determining separate velocity components of an acoustic wavefield that are incident on a distributed fiber optic sensor are disclosed. A fiber optic sensor includes fiber that is spatially distributed in non-parallel planes of a three-dimensional volume having three orthogonal axes. The fiber includes a first fiber pattern that is spatially distributed within a first plane of the three-dimensional volume, and a second fiber pattern that is spatially distributed within a second plane of the volume. The fiber patterns are interrogated separately by a distributed fiber optic interrogation system. The individual responses from each pattern are combined and processed to determine separate velocity components of the acoustic wavefield relative to the orthogonal axes of the three-dimensional volume.

An apparatus and method for correcting the wavenumber sensitivity of a distributed fiber optic sensor are disclosed. The distributed fiber optic sensor is deployed in a region of interest to measure a characteristic of an incident acoustic wavefield. A composite response of the distributed sensor is determined based on backscatter optical signals generated by the sensor, where the composite response is indicative of a characteristic of an incident acoustic wavefield. The composite response includes at least a first response having a first wavenumber sensitivity and a second response having a second wavenumber sensitivity. The second wavenumber sensitivity is selected so that wavenumber notches of the first and second responses do not overlap.

An apparatus and method for correcting the wavenumber sensitivity of a distributed fiber optic sensor are disclosed. The distributed fiber optic sensor is deployed in a region of interest to measure a characteristic of an incident acoustic wavefield. A composite response of the distributed sensor is determined based on backscatter optical signals generated by the sensor, where the composite response is indicative of a characteristic of an incident acoustic wavefield. The composite response includes at least a first response having a first wavenumber sensitivity and a second response having a second wavenumber sensitivity. The second wavenumber sensitivity is selected so that wavenumber notches of the first and second responses do not overlap.

A fluid flow meter can include a sensor capable of transmitting a transmit signal to propagate, at least partially, through a fluid in a pipe and receiving a respective receive signal. The fluid flow meter can include a memory storing computer code instructions and a plurality of pipe type signatures associated with a plurality of pipe types. Each pipe type signature of a respective pipe type of the plurality of pipe types can include one or more characteristics of receive signals associated with that pipe type. The fluid flow meter can also include a processor communicatively coupled to the sensor and to the memory. When executing the computer code instructions, the processor can determine one or more signal features of the receive signal, and identify a pipe type of the pipe based on the one or more signal features of the receive signal and the plurality of pipe type signatures.