Disclosed is an echosounder configured to: a) drive the transducers of its emitting antenna to emit first and second acoustic waves having first and second frequencies, these waves being superposed over one another along an axis of superposition that is directed toward a point of the bottom of the subaquatic environment, and b) acquire an echo signal, the frequency of which is equal to the difference between the first and the second frequencies, the echosounder being configured to perform steps a) and b) a plurality of times while varying the orientation of the axis of superposition, and to determine, on the basis of the acquired echo signals, an image representative of the content of the sub-bottom of the subaquatic environment beneath each of the points. Also disclosed is an associated method for characterizing a portion of the sub-bottom of a subaquatic environment.

The invention relates to the use of sonar acoustic pulses to provide information about the status and composition of aquaculture farming tanks or ponds. In particular, the invention is directed to processes and systems comprising: a acoustic pulse transducer configured to transmit a acoustic pulse into an aquaculture farming tank or pond, a network of underwater sonar signal receivers; a computer connected to the network of underwater sonar signal receivers, said computer having a processor and memory, said memory having computer programming instructions saved thereon and executable on the processor, said computer programming instructions configured for receiving and comparing a signal difference between the acoustic pulse and the scattered return signal and for using the signal difference to output a signal difference data point related to a calculated shrimp biomass and distribution in the aquaculture farming tank or pond; a computer display connected to the computer and configured to display the signal difference data point related the calculated shrimp biomass and distribution.

The invention relates to the use of sonar acoustic pulses to provide information about the status and composition of aquaculture farming tanks or ponds. In particular, the invention is directed to processes and systems comprising: a acoustic pulse transducer configured to transmit a acoustic pulse into an aquaculture farming tank or pond, a network of underwater sonar signal receivers; a computer connected to the network of underwater sonar signal receivers, said computer having a processor and memory, said memory having computer programming instructions saved thereon and executable on the processor, said computer programming instructions configured for receiving and comparing a signal difference between the acoustic pulse and the scattered return signal and for using the signal difference to output a signal difference data point related to a calculated shrimp biomass and distribution in the aquaculture farming tank or pond; a computer display connected to the computer and configured to display the signal difference data point related the calculated shrimp biomass and distribution.

An ultrasonic wave measuring device including an ultrasonic wave device and a processor. The ultrasonic wave device transmits transmission ultrasonic waves toward an object, receives reflected ultrasonic waves, and outputs reception signals. The processor is configured to: detect a transmission time; detect zero-crossing points of the reception signals; detect zero-crossing times; calculate periods of time between the transmission time and each of the zero-crossing times; compare a reference period of time with each of the calculated periods of time so as to generate difference values therebetween; determine a minimum value among the difference values; and set a corresponding zero-crossing point having the minimum value as a reception zero-crossing point. The ultrasonic wave measuring device is configured to measure a distance toward the object based on the period of time between the zero-crossing time corresponding to the reception zero-crossing point and the transmission time.

Techniques are provided for implementing an end-fire synthetic aperture sonar system. A methodology implementing the techniques according to an embodiment includes generating a plurality of matched-filtered signals (pings) based on correlations of a transmitted sonar signal with a plurality of reflected or scattered returns of the transmitted signal received from a hydrophone, the reflected or scattered returns associated with a plurality of locations of the hydrophone relative to a location of a transmitter. The method further includes generating a coarse estimate of the locations of the hydrophone based on incoherent cross correlations of the pings, and generating a refined estimate of the locations of the hydrophone based on the coarse estimate and further based on coherent cross correlations of the pings. The method further includes performing delay-and-sum beamforming to combine the pings, the beamforming employing time delays based on the estimated locations of the hydrophone.

A method is provided for classifying an object, in particular in the surroundings of a motor vehicle, using an ultrasonic sensor system, the ultrasonic sensor system including a plurality of spatially distributed ultrasonic sensors. A plurality of measurements are carried out continuously during a measurement, an ultrasonic signal being emitted by one of the ultrasonic sensors, a signal being received by at least one of the ultrasonic sensors which includes a plurality of reflected echo signals, so-called multiple echoes, and the received echo signals being associated with an object. A plurality of features may be determined from the received echo signals. The object is classified as a function of a combination of at least two of these features, in particular as a pedestrian.

Disclose are various approaches for optimizing operation of an autonomous wireless mobile asset monitoring system. The approaches involve detecting the presence of cargo in a mobile asset. First, if energy conservation is a requirement of the system, each zone of the mobile asset is scanned until cargo is detected in one of the zones. Then, the results of the scan are transmitted to backend infrastructure. Alternatively, if energy conservation is not a requirement of the system, every zone of the mobile asset is scanned and the results of the scan are transmitted to backend infrastructure.

Disclose are various approaches for optimizing operation of an autonomous wireless mobile asset monitoring system. The approaches involve detecting the presence of cargo in a mobile asset. First, if energy conservation is a requirement of the system, each zone of the mobile asset is scanned until cargo is detected in one of the zones. Then, the results of the scan are transmitted to backend infrastructure. Alternatively, if energy conservation is not a requirement of the system, every zone of the mobile asset is scanned and the results of the scan are transmitted to backend infrastructure.

A method for use in acoustic imaging, comprising: transmitting, from a transmitter, a first sound wave pulse at a first frequency determined by a maximum sampling rate of a receiver; transmitting at least one second sound wave pulse at a frequency substantially equal to the first frequency, the first and at least one second sound wave pulses being transmitted substantially within a fraction of a sample interval of the receiver; receiving and sampling, at the receiver, a reflection of at least two of the first and at least one second pulses to generate a set of receiver samples; and expanding the set of receiver samples, based on the first frequency and a total number of the first and at least one second pulses transmitted, to generate an expanded sample set with a larger number of samples than the set of receiver samples.

A method for use in acoustic imaging, comprising: transmitting, from a transmitter, a first sound wave pulse at a first frequency determined by a maximum sampling rate of a receiver; transmitting at least one second sound wave pulse at a frequency substantially equal to the first frequency, the first and at least one second sound wave pulses being transmitted substantially within a fraction of a sample interval of the receiver; receiving and sampling, at the receiver, a reflection of at least two of the first and at least one second pulses to generate a set of receiver samples; and expanding the set of receiver samples, based on the first frequency and a total number of the first and at least one second pulses transmitted, to generate an expanded sample set with a larger number of samples than the set of receiver samples.