An acoustic antenna intended to equip a sonar, the antenna being centred around a first longitudinal axis and includes at least a first assembly of at least two transducers and a second assembly of at least two transducers stacked along the longitudinal axis, each transducer having at least a radial mode having a resonance frequency, referred to as the radial frequency, and a cavity mode having a resonance frequency, referred to as the cavity frequency, wherein the transducers of the first assembly are configured to transmit sound waves in a first continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the first assembly and the transducers of the second assembly are configured to transmit sound waves in a second continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the second assembly, in that the cavity frequency of a transducer of the second assembly is equal to the radial frequency of a transducer of the first assembly plus or minus (fr1fc1)/10, fr1 being the radial frequency of the transducer of the first assembly and fc1 being the cavity frequency of the transducers of the first assembly and wherein the transducers of the second assembly are positioned between the transducers of the first assembly and in that no transducer of the first assembly is positioned between the transducers of the second assembly.

An acoustic antenna intended to equip a sonar, the antenna being centred around a first longitudinal axis and includes at least a first assembly of at least two transducers and a second assembly of at least two transducers stacked along the longitudinal axis, each transducer having at least a radial mode having a resonance frequency, referred to as the radial frequency, and a cavity mode having a resonance frequency, referred to as the cavity frequency, wherein the transducers of the first assembly are configured to transmit sound waves in a first continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the first assembly and the transducers of the second assembly are configured to transmit sound waves in a second continuous frequency band extending at least between the cavity and radial frequencies of the transducers of the second assembly, in that the cavity frequency of a transducer of the second assembly is equal to the radial frequency of a transducer of the first assembly plus or minus (fr1fc1)/10, fr1 being the radial frequency of the transducer of the first assembly and fc1 being the cavity frequency of the transducers of the first assembly and wherein the transducers of the second assembly are positioned between the transducers of the first assembly and in that no transducer of the first assembly is positioned between the transducers of the second assembly.

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

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

An object detection device includes a transceiver configured to transmit/receive an ultrasonic wave; a drive signal generation unit configured to generate a drive signal for driving the transceiver; a transmitter circuit configured to cause the transceiver to transmit a probe wave, which is an ultrasonic wave, by driving the transceiver based on the drive signal; and a receiver circuit configured to generate a reception signal corresponding to a reception result of the ultrasonic wave of the transceiver, wherein the drive signal generation unit is configured to generate the drive signal so that frequency of the probe wave changes over time. The device further includes: a voltage measurement unit configured to measure a voltage signal generated in the transceiver while the transceiver transmits the probe wave with frequency changing over time; and a state determination unit configured to make a state determination regarding the transceiver based on the voltage signal.

An object detection device includes a transceiver configured to transmit/receive an ultrasonic wave; a drive signal generation unit configured to generate a drive signal for driving the transceiver; a transmitter circuit configured to cause the transceiver to transmit a probe wave, which is an ultrasonic wave, by driving the transceiver based on the drive signal; and a receiver circuit configured to generate a reception signal corresponding to a reception result of the ultrasonic wave of the transceiver, wherein the drive signal generation unit is configured to generate the drive signal so that frequency of the probe wave changes over time. The device further includes: a voltage measurement unit configured to measure a voltage signal generated in the transceiver while the transceiver transmits the probe wave with frequency changing over time; and a state determination unit configured to make a state determination regarding the transceiver based on the voltage signal.

A driving device includes a transmission wave signal generation circuit configured to generate a transmission wave signal, and a driving circuit configured to drive an ultrasonic oscillation element based on the transmission wave signal. The driving circuit has an initial driving sequence in which the driving circuit generates the transmission wave signal at an initial frequency, a first transition sequence in which the driving circuit generates the transmission wave signal during its transition from the initial frequency to a first frequency, and a second transition sequence in which the driving circuit generates the transmission wave signal during its transition from the first frequency to a second frequency. The initial frequency and the second frequency are closer than the first frequency, to the resonance frequency of the ultrasonic oscillation element. The first transition sequence is allotted a longer time than the time allotted to the second transition sequence.

A driving device includes a transmission wave signal generation circuit configured to generate a transmission wave signal, and a driving circuit configured to drive an ultrasonic oscillation element based on the transmission wave signal. The driving circuit has an initial driving sequence in which the driving circuit generates the transmission wave signal at an initial frequency, a first transition sequence in which the driving circuit generates the transmission wave signal during its transition from the initial frequency to a first frequency, and a second transition sequence in which the driving circuit generates the transmission wave signal during its transition from the first frequency to a second frequency. The initial frequency and the second frequency are closer than the first frequency, to the resonance frequency of the ultrasonic oscillation element. The first transition sequence is allotted a longer time than the time allotted to the second transition sequence.

A sound wave processing device includes a transmission signal generation unit that generates a transmission signal for transmitting a sound wave, a received wave signal output unit that outputs a received wave signal based on receiving the sound wave, a correlation-convolution integral processing unit that performs correlation-convolution integral processing in parallel for each reference wave data, on the basis of the received wave signal and a plurality of reference wave data, and an own wave identification unit that determines whether or not the received sound wave is own wave, which is a reflected wave of the sound wave transmitted by the transmission signal generation unit, on the basis of a correlation-convolution integral value output from the correlation-convolution integral processing unit.

A sound wave processing device includes a transmission signal generation unit that generates a transmission signal for transmitting a sound wave, a received wave signal output unit that outputs a received wave signal based on receiving the sound wave, a correlation-convolution integral processing unit that performs correlation-convolution integral processing in parallel for each reference wave data, on the basis of the received wave signal and a plurality of reference wave data, and an own wave identification unit that determines whether or not the received sound wave is own wave, which is a reflected wave of the sound wave transmitted by the transmission signal generation unit, on the basis of a correlation-convolution integral value output from the correlation-convolution integral processing unit.