A method and apparatus for monitoring a structure using an optical fiber based distributed acoustic sensor (DAS) extending along the length of the structure. The DAS is able to resolve a separate acoustic signal with a spatial resolution of 1 m along the length of the fibre, and hence is able to operate with an acoustic positioning system to determine the position of the riser with the same spatial resolution. In addition, the fiber can at the same time also detect much lower frequency mechanical vibrations in the riser, for example such as resonant mode vibrations induced by movement in the surrounding medium. By using vibration detection in combination with acoustic positioning then overall structure shape monitoring can be undertaken, which is useful for vortex induced vibration (VIV) visualisation, fatigue analysis, and a variety of other advanced purposes. The structure may be a sub-sea riser.

The present application provides an intelligent device, an intelligent speaker, and a method and system for controlling the same. The intelligent device includes a first sound detection module configured to detect a first sound signal directly reaching the first sound detection module; an angle determination module configured to determine a time difference between the receiving time of the first sound signal and the receiving time of the second sound signal, and determine a relative angle between the intelligent device and the intelligent speaker based on a distance between the first sound detection module and the second sound detection module and the time difference; and a transmitting module configured to transmit a notification message containing the relative angle to the intelligent speaker, so that the intelligent speaker directionally transmits a sound to the intelligent device based on the relative angle. Directional sounding based on relative angle calculation is realized.

The present application provides an intelligent device, an intelligent speaker, and a method and system for controlling the same. The intelligent device includes a first sound detection module configured to detect a first sound signal directly reaching the first sound detection module; an angle determination module configured to determine a time difference between the receiving time of the first sound signal and the receiving time of the second sound signal, and determine a relative angle between the intelligent device and the intelligent speaker based on a distance between the first sound detection module and the second sound detection module and the time difference; and a transmitting module configured to transmit a notification message containing the relative angle to the intelligent speaker, so that the intelligent speaker directionally transmits a sound to the intelligent device based on the relative angle. Directional sounding based on relative angle calculation is realized.

The present disclosure relates to an acoustic position determination system that includes a mobile communication device and at least one base transmitter unit. The mobile communication device is configured to identify a peak in the received signal, and to de-convolve the signal with all codes that are relevant to the area in which the signal is received. A joint likelihood that a potential code is correct is formed by determining a likelihood based on a signal parameter such as signal-to-noise ratio and a likelihood based on time-of arrival information.

The present disclosure relates to an acoustic position determination system that includes a mobile communication device and at least one base transmitter unit. The mobile communication device is configured to identify a peak in the received signal, and to de-convolve the signal with all codes that are relevant to the area in which the signal is received. A joint likelihood that a potential code is correct is formed by determining a likelihood based on a signal parameter such as signal-to-noise ratio and a likelihood based on time-of arrival information.

A method is provided for localizing an underwater vehicle using acoustic ranging. The method includes receiving, using an acoustic receiver, a time series signal based on one or more acoustic signals transmitted from an acoustic source having a known location; determining a travel time of the waveform from the known location of the acoustic source to the acoustic receiver; and determining a range of the underwater vehicle with respect to the acoustic source based on the travel time of the waveform and a sound speed field taken along a ray trajectory extending from the known location of the acoustic source and intersecting with the acoustic receiver at an expected arrival time and depth of the acoustic signal at the underwater vehicle.

A method is provided for localizing an underwater vehicle using acoustic ranging. The method includes receiving, using an acoustic receiver, a time series signal based on one or more acoustic signals transmitted from an acoustic source having a known location; determining a travel time of the waveform from the known location of the acoustic source to the acoustic receiver; and determining a range of the underwater vehicle with respect to the acoustic source based on the travel time of the waveform and a sound speed field taken along a ray trajectory extending from the known location of the acoustic source and intersecting with the acoustic receiver at an expected arrival time and depth of the acoustic signal at the underwater vehicle.

A device (10) for detecting a signal of interest in order to locate an underwater source of the signal. The device includes a receiver (13) configured to detect the signal of interest, an actuator (14) configured to allow at least a portion of the detection device (10) to move towards a zone indicating a result of detection of the signal of interest in response to the receiver being operated, and an emitter (15) configured to indicate the result of detection of the signal of interest.

A device (10) for detecting a signal of interest in order to locate an underwater source of the signal. The device includes a receiver (13) configured to detect the signal of interest, an actuator (14) configured to allow at least a portion of the detection device (10) to move towards a zone indicating a result of detection of the signal of interest in response to the receiver being operated, and an emitter (15) configured to indicate the result of detection of the signal of interest.

An apparatus, method and computer program, the apparatus comprising: processing circuitry; and memory circuitry including computer program code, the memory circuitry and the computer program code configured to, with the processing circuitry, enable the apparatus to: enable a wireless connection to be established with an electronic device; capture an audio signal and enable the captured audio signal to be sent to the electronic device using the wireless connection to enable the captured audio signal to be used to create an enhanced audio signal; and wherein the apparatus is arranged to be removeably attachable to the electronic device.