Sensor receiver nulls and null steering. One example embodiment is method in which a direction from a sensor position to a noise source is determined. A coordinate rotation is applied to a first set of signal values, wherein each signal value of the first set of signal values is based on an output of a corresponding component of a three-component particle motion sensor at the sensor position. The applying generates a rotated set of signal values. The coordinate rotation comprises a coordinate rotation transforming a first set of coordinate axes to a second set of coordinate axes, wherein the first set of coordinate axes has each coordinate axis aligned with a corresponding component of the three-component particle motion sensor at the sensor position, and the second set of coordinate axes comprises a first axis pointed in a direction opposite the direction from the sensor position to the noise source.

Disclosed is a method and system for diffraction-aware non-line of sight (NLOS) sound source localization (SSL) that may reconstruct an indoor space, may generate acoustic rays into the indoor space based on an audio signal collected from the indoor space, and may estimate a position of an NLOS sound source based on a point at which one of the acoustic rays is diffracted.

Passive location of an emitter is achieved by sensing a signal propagated from the emitter at multiple sensing locations and determining its phase at each sensing location. A three-dimensional region is searched to find an emitter location for which phase estimates of the signal at the emitter location are in good agreement among the sensing locations. An iterative search from a set of starting points in the region may be performed. The region may be subdivided and each region searched in parallel using multiple processors in parallel. Phase at the sensing locations may be determined locally, using synchronized clocks at the sensing locations, or at a common receiver. In the latter case, signal propagation time from the sensing location to the receiver location is taken into account. The emitter may be a wireless endoscopy capsule, for example.

Passive location of an emitter is achieved by sensing a signal propagated from the emitter at multiple sensing locations and determining its phase at each sensing location. A three-dimensional region is searched to find an emitter location for which phase estimates of the signal at the emitter location are in good agreement among the sensing locations. An iterative search from a set of starting points in the region may be performed. The region may be subdivided and each region searched in parallel using multiple processors in parallel. Phase at the sensing locations may be determined locally, using synchronized clocks at the sensing locations, or at a common receiver. In the latter case, signal propagation time from the sensing location to the receiver location is taken into account. The emitter may be a wireless endoscopy capsule, for example.

A method for establishing timing and processing of network messages in a wireless ad-hoc network comprising: establishing a network identification (ID) when the wireless ad-hoc network is unestablished; and establishing a local timing in the wireless ad-hoc network, the local timing having a network data frame structure, each network data frame in the network data frame structure having a plurality of network slot times, wherein each network slot time is designated as one of an assigned network slot time or a shared network slot time, each wireless node in the wireless ad-hoc network designated as one of an assigned wireless node or an unassigned wireless node, each assigned wireless node initiating and transmitting network messages in a corresponding assigned network slot time or any available shared network slot time, and each unassigned wireless node initiating and transmitting network messages only in any available shared network slot time.

A method for establishing timing and processing of network messages in a wireless ad-hoc network comprising: establishing a network identification (ID) when the wireless ad-hoc network is unestablished; and establishing a local timing in the wireless ad-hoc network, the local timing having a network data frame structure, each network data frame in the network data frame structure having a plurality of network slot times, wherein each network slot time is designated as one of an assigned network slot time or a shared network slot time, each wireless node in the wireless ad-hoc network designated as one of an assigned wireless node or an unassigned wireless node, each assigned wireless node initiating and transmitting network messages in a corresponding assigned network slot time or any available shared network slot time, and each unassigned wireless node initiating and transmitting network messages only in any available shared network slot time.

Further improvement in usability is promoted. An information processing apparatus (10) includes: an acquisition unit (111) configured to acquire information regarding at least one candidate location; a generation unit (1122) configured to generate sound data for expressing a sense of distance from a current location of a user to the candidate location acquired by the acquisition unit (111) using a plurality of sound sources; and an output unit (113) configured to output the sound data generated by the generation unit (1122) to the plurality of sound sources.

Further improvement in usability is promoted. An information processing apparatus (10) includes: an acquisition unit (111) configured to acquire information regarding at least one candidate location; a generation unit (1122) configured to generate sound data for expressing a sense of distance from a current location of a user to the candidate location acquired by the acquisition unit (111) using a plurality of sound sources; and an output unit (113) configured to output the sound data generated by the generation unit (1122) to the plurality of sound sources.

A method includes obtaining acoustic data from a plurality of acoustic sensors disposed on one or more mobile systems, one or more fixed infrastructure elements, or a combination thereof. The method includes obtaining image data from a plurality of image sensors disposed on the one or more mobile systems, the one or more fixed infrastructure elements, or a combination thereof. The method includes determining whether the anomalous state is present based on the image data and the acoustic data. The method includes, in response to the anomalous state being satisfied, identifying a location associated with the anomalous state based on the acoustic data and the image data and transmitting a notification based on the anomalous state and the location.

An underwater communications network may include spaced apart nodes on a bottom of a body of water. The underwater communications network may also include fiber optic cabling connecting the spaced apart nodes. Each node may include a frame, a node short-range navigation device carried by the frame, and an unmanned underwater vehicle (UUV) carried by the frame after delivering a fiber optic cable along a navigation path from an adjacent node. The UUV may be configured to cooperate with the node short-range navigation device during an end portion of the navigation path adjacent the frame.