A position detection system is provided as including (i) a sound wave apparatus in a predetermined designated area and (ii) a detection terminal. The sound wave apparatus transmits a sound wave on which position information including a position of its own is superimposed as a detection sound wave. The detection terminal receives the detection sound wave, acquires the position information superimposed on the received detection sound wave, and stores the acquired position information as information indicating the position of the designated area.

A driving support apparatus according to the present disclosure includes a memory and a hardware processor coupled to the memory and a sound wave sensor. The hardware processor is configured to select, as a transmission and reception scheme, either a pulse scheme or a spread spectrum modulation scheme, and control the sound wave sensor with the selected transmission and reception scheme. When the spread spectrum modulation scheme is selected as the transmission and reception scheme, the hardware processor causes the sound wave sensor to successively transmit and receive sound waves by using the spread spectrum modulation scheme.

An electronic device (1) such as a cell phone, or a proximity detector for an electronic device (1), has an ultrasound transmitter (5), an ultrasound receiver (6), and a processing system. It transmits an ultrasonic sine-wave signal from the transmitter (5), and receives the ultrasonic sine-wave signal, through air, at the receiver (6). It detects when the frequency of the transmitted signal and a frequency of the received signal satisfy a predetermined difference criterion, and uses this to determine whether to disable or enable a touch or touchless input (2) on the device (1).

A survey system including a multibeam echo sounder and a beam selector for selecting beams with the largest amplitudes.

A method for operating an ultrasonic sensor is provided, a plurality of measuring cycles being consecutively carried out. In each measuring cycle, an electroacoustic transducer of the ultrasonic sensor is excited to carry out mechanical oscillations with the aid of an excitation pulse, whereby a measuring signal is transmitted by the transducer, an echo signal is received by the transducer, and a piece of object information is ascertained from the echo signal. The frequency profile of the excitation pulse differs in measuring cycles which are carried out chronologically consecutively, the frequency profile of an excitation pulse being selected in each measuring cycle randomly or according to a predefined sequence from a group of predefined frequency profiles.

The present technology relates to a distance measuring apparatus, a distance measuring method, and a program that enable accurate measurement of the distance to a target. A distance measuring apparatus according to one aspect of the present technology includes: an OFDM modulation unit configured to generate an OFDM signal by performing OFDM modulation on a transmission signal; an output unit configured to output the OFDM signal by using an ultrasonic wave as a carrier wave; a collecting unit configured to collect, as a reception signal, an ultrasonic wave as a reflected wave from a target of the ultrasonic wave output from the output unit; a demodulation unit configured to generate a demodulated signal by demodulating the reception signal; a calculation unit configured to calculate a delay profile on the basis of an own signal obtained in the process of generating the OFDM signal and the demodulated signal; and an arithmetic operation unit configured to determine delay time of the ultrasonic wave from the delay profile and to arithmetically operate the distance to the target on the basis of the delay time. The present technology can be applied to, for example, an automobile.

In an ultrasonic detection system that uses frequency-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses dynamic thresholding to discriminate valid echoes from system and environmental noise in multiple envelope signals produced by multiple correlators. The time-varying dynamic thresholds are generated from the mean of noise in a respective envelope derived from the output of a respective correlator. Multiple thresholds can be combined together such that a single time-varying threshold is applied to all correlators' envelopes. Such thresholding has the benefits of a constant false-alarm rate with regard to detection of echoes (as opposed to false triggering from noise), and, owing to finer-resolution and adaptive thresholds, can detect targets or obstacles as further distances and with greater time responsiveness.

A survey system including a transmitter, receiver, projector array and hydrophone array transmits and receives sound waves to perform one or more survey missions.

Some methods may involve receiving a first content stream that includes first audio signals, rendering the first audio signals to produce first audio playback signals, generating first direct sequence spread spectrum (DSSS) signals, generating first modified audio playback signals by inserting the first DSSS signals into the first audio playback signals, and causing a loudspeaker system to play back the first modified audio playback signals, to generate first audio device playback sound. The method(s) may involve receiving microphone signals corresponding to at least the first audio device playback sound and to second through N.sup.th audio device playback sound corresponding to second through N.sup.th modified audio playback signals (including second through N.sup.th DSSS signals) played back by second through Nth audio devices, extracting second through N.sup.th DSSS signals from the microphone signals and estimating at least one acoustic scene metric based, at least partly, on the second through N.sup.th DSSS signals.

In an ultrasonic detection system that uses frequency-modulation or phase-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses peak search, peak buffer, and peak rank stages in one or more receiver signal processing paths to identify valid received ultrasonic signal envelope peaks in correlator outputs. The peak rank stage can support different modes respectively designed to handle one code, two or more codes, or two or more codes with support for Doppler frequency shift detection. Valid peak information (e.g., amplitude and time) can be reported to a central controller and/or stored locally in a fusion stage to generate more intelligent information for targets or obstacles using peaks from multiple bursts.