In a sonar system using a large array multielement sonar detector, the raw phase and intensity data is reduced to less than three bits per channel per slice for each of the detectors in the multielement array before the raw data is transmitted to a beamformer for transforming the data to information about the spatial positions of objects reflecting the sonar signals.

In one embodiment, a method includes transmitting, from a first transducer of an electronic device, a first audio signal to a surface near the electronic device. The first audio signal is generated based on a frequency sweep across a range of frequencies. The method also includes receiving, at a second transducer of the electronic device, a second audio signal that is at least partly reflected off the surface. The method then determines an attribute of the surface based on the received second audio signal.

In one embodiment, a method includes transmitting, from a first transducer of an electronic device, a first audio signal to a surface near the electronic device. The first audio signal is generated based on a frequency sweep across a range of frequencies. The method also includes receiving, at a second transducer of the electronic device, a second audio signal that is at least partly reflected off the surface. The method then determines an attribute of the surface based on the received second audio signal.

Systems and methods are disclosed in which a playback device transmits a first sound signal including a predetermined waveform. In one example, the playback device receives a second sound signal including at least one reflection of the first sound signal. The second sound signal is processed to determine a location of a person relative to the playback device, and a characteristic of audio reproduction by the playback device is selected, based on the determined location of the person.

A marine multibeam sonar device comprises a processing element and a transmitter. The processing element generates a plurality of transmit transducer electronic signals and inverts a polarity of a first portion of the transmit transducer electronic signals. The transmitter is in communication with the processing element and includes a plurality of transmit electronic circuits and a plurality of transmit transducers. Each transmit electronic circuit receives and processes one of the transmit transducer electronic signals, wherein a first portion of the circuits re-inverts the polarity of the first portion of the transmit transducer electronic signals. The transmit transducers receive the processed transmit transducer electronic signals from the transmit electronic circuits and generate a sonar beam.

A marine multibeam sonar device comprises a processing element and a transmitter. The processing element generates a plurality of transmit transducer electronic signals and inverts a polarity of a first portion of the transmit transducer electronic signals. The transmitter is in communication with the processing element and includes a plurality of transmit electronic circuits and a plurality of transmit transducers. Each transmit electronic circuit receives and processes one of the transmit transducer electronic signals, wherein a first portion of the circuits re-inverts the polarity of the first portion of the transmit transducer electronic signals. The transmit transducers receive the processed transmit transducer electronic signals from the transmit electronic circuits and generate a sonar beam.

A method of and apparatus for processing received radiation (e.g. RADAR radiation) reflected from a target, the method comprising generating a set of predicted targets, the set of predicted targets comprising at least one member, each member representing a state of the target, generating a predicted waveform for the radiation for each member dependent upon the state of the target, and comparing each predicted waveform with a waveform of the received radiation to determine the accuracy with which the state of the target represented by the member for which the predicted waveform was generated matches an actual state of the target.

A method of and apparatus for processing received radiation (e.g. RADAR radiation) reflected from a target, the method comprising generating a set of predicted targets, the set of predicted targets comprising at least one member, each member representing a state of the target, generating a predicted waveform for the radiation for each member dependent upon the state of the target, and comparing each predicted waveform with a waveform of the received radiation to determine the accuracy with which the state of the target represented by the member for which the predicted waveform was generated matches an actual state of the target.

A system for tracking wearable user devices is provided herein. The system may include a tracking environment, comprising: one or more scene light sources, wherein the location of the scene light sources is known within said tracking environment; one or more scene detectors operable to detect light within the tracking environment, wherein the location and orientation of said one or more scene detectors is known within said tracking environment; one or more scene reflectors operable to reflect light originating from said one or more scene light sources, wherein the location of said one or more scene reflectors is known within said tracking environment; and, one or more wearable user devices comprising a curved reflective surface with known geometry; and, a computer processor operable to analyse light readings detected by said one or more scene detectors, and to calculate a position of the one or more wearable user devices.

Embodiments include apparatus and method for collecting observation data for updating a geographic database. An initial observation is collected by a first mobile device, a first vehicle, or a first sensor. Along with the geographic position, data indicative of the first observation is send to a server. The central server may analyze of the initial observation data to determine if additional observations should be made and define a bounding box from the geographic position of the first mobile device and the analysis of the initial observation data. A request for additional observations is generated and sent to at least one second mobile device, second vehicle, or second sensor based on the bounding box.