Disclosed is a SONAR system operable to transmit a pair of pulses including an up-chirp signal and a down-chirp signal wherein the down-chirp signal is a time-reversed version of the up-chirp signal. Also disclosed is a related method of operation.

Techniques for calibrating presence-detection devices to account for various factors that can affect the presence-detection devices' ability to detect movement. Presence-detection devices may detect movement of a person in an environment by emitting ultrasonic signals into the environment, and characterizing the change in the frequency, or the Doppler shift, of the reflections of the ultrasonic signals off the person caused by the movement of the person. However, factors such as environmental acoustic conditions, noise sources, etc., may affect the ability of the presence-detection devices to detect movement. To calibrate for these factors, the presence-detection devices may use a loudspeaker to emit an ultrasonic sweep signal that spans different frequencies in an ultrasonic frequency range. The presence-detection devices may generate audio data using a microphone that represents the ultrasonic sweep signal, and analyze that audio data to determine an optimal frequency range and/or transmission power for subsequent ultrasonic signal transmissions.

A sonar system is provided including a sonar assembly configured to attach to a motor assembly of a watercraft or a watercraft. The sonar assembly includes sonar transducer element(s) that transmit sonar beam(s). The sonar system includes a display, processor(s), and a steering assembly configured to cause rotation of the sonar assembly or the motor assembly. The sonar system includes a memory including computer program code that causes the processor(s) to cause the sonar transducer element(s) to emit sonar beam(s), receive sonar return data from a coverage volume of the sonar transducer element(s), generate a sonar image of the coverage volume based on the sonar return data, receive an input from a user, determine a target in the underwater environment based on the input, and cause the steering assembly to adjust the coverage volume to maintain the target within the coverage volume as the watercraft moves relative to the target.

An object detection device includes: a transmission/reception unit that has a vibrator capable of transmitting and receiving ultrasound, that causes the vibrator to transmit transmission signals at different timings, and that receives the reception signals returning after being reflected on a circumferentially existing object; an acquisition unit that acquires a first distance to the object, based on a time difference between a transmission timing of a first transmission signal and a reception timing of a first reception signal, and that acquires a relative speed of the object, based on a frequency difference between the first transmission signal and the first reception signal; an estimation unit that estimates a second distance to the object at a transmission timing of a second transmission signal to be transmitted subsequently to the first transmission signal; and an adjustment unit that adjusts the number of waves or a transmission time of the second transmission signal.

Sensing apparatus includes a radiation source, which emits pulses of optical radiation toward multiple points in a target scene. A receiver receives the optical radiation that is reflected from the target scene and outputs signals that are indicative of respective times of flight of the pulses to and from the points in the target scene. Processing and control circuitry selects a first pulse repetition interval (PRI) and a second PRI, greater than the first PRI, from a permitted range of PRIs, drives the radiation source to emit a first sequence of the pulses at the first PRI and a second sequence of the pulses at a second PRI, and processes the signals output in response to both the first and second sequences of the pulses in order to compute respective depth coordinates of the points in the target scene.

Sensing apparatus includes a radiation source, which emits pulses of optical radiation toward multiple points in a target scene. A receiver receives the optical radiation that is reflected from the target scene and outputs signals that are indicative of respective times of flight of the pulses to and from the points in the target scene. Processing and control circuitry selects a first pulse repetition interval (PRI) and a second PRI, greater than the first PRI, from a permitted range of PRIs, drives the radiation source to emit a first sequence of the pulses at the first PRI and a second sequence of the pulses at a second PRI, and processes the signals output in response to both the first and second sequences of the pulses in order to compute respective depth coordinates of the points in the target scene.

A method for recognizing a noise represented in a receive signal of an ultrasonic sensor. A characteristic spectrum of the noise is compared with a noise spectrum of the receive signal, the noise spectrum including at least two noise levels determined in different frequency bands of the receive signal.

A method for recognizing a noise represented in a receive signal of an ultrasonic sensor. A characteristic spectrum of the noise is compared with a noise spectrum of the receive signal, the noise spectrum including at least two noise levels determined in different frequency bands of the receive signal.

A device and method used to increase the resolution when imaging, measuring and inspecting wells, pipes and objects located therein. The device comprises an array of acoustic transducers that both transmit and receive acoustic signals. Scan lines may be overlapped by interlacing transmission and receiving windows thus increasing either the resolution or logging speed drastically compared to conventional approaches. The sequence of the scan lines making up an imaging frame is created by stratifying physically close lines and randomly selecting from within each stratum, preventing interference from neighboring transducers, signals and acoustic artifacts that fundamentally limit logging speed and resolution using conventional methods.

A device and method used to increase the resolution when imaging, measuring and inspecting wells, pipes and objects located therein. The device comprises an array of acoustic transducers that both transmit and receive acoustic signals. Scan lines may be overlapped by interlacing transmission and receiving windows thus increasing either the resolution or logging speed drastically compared to conventional approaches. The sequence of the scan lines making up an imaging frame is created by stratifying physically close lines and randomly selecting from within each stratum, preventing interference from neighboring transducers, signals and acoustic artifacts that fundamentally limit logging speed and resolution using conventional methods.