Aquatic tracking makes use of acoustics, rather than other signals that do not travel as well in water. Tracking devices are used to monitor species of fish and other aquatic animals to monitor how their populations and movements are in nature, and how or whether those populations and movements are affected by, for example, hydroelectric dams and other manmade structures and phenomena. Often, the trackers inserted in aquatic animals adversely affect the animals and can lead to mortality or changed behaviors. New solutions that decrease the size and weight of such tracking devices are disclosed herein, enabling better tracking of aquatic animals that is less likely to cause adverse effects to those populations.

An object detection device includes a signal generation unit, a drive unit, an object determination unit, and a drive control unit. The signal generation unit generates at least one pulse signal that includes an identification code for identifying the ultrasonic wave. The drive unit drives the wave transceiver unit using a current or a voltage according to the at least one pulse signal. The object determination unit compares a code included in the received ultrasonic wave with the identification code and determines whether the received ultrasonic wave is a wave resulting from reflection of the ultrasonic wave transmitted by the wave transceiver unit, and determines whether an object is present in a predetermined detection range based on the amplitude of the received ultrasonic wave. The drive control unit reduces the current or the voltage used by the drive unit when a predetermined amplitude rise time has elapsed.

A sonar survey system and method excites reflectors using a broadband message that excites all frequencies within the band providing for selection and evaluation of frequencies of interest after the survey is completed.

A system for detecting objects using ultrasonic waves and methods for making and using the same are provided. The object detection system uniquely encodes each of a plurality of ultrasonic waves and transmit each of the uniquely-encoded ultrasonic waves in a respective direction. The object detection system then receives any of the emitted uniquely-encoded ultrasonic waves that are reflected from an object. By decoding the reflected ultrasonic waves, the object detection system distinguishes among the uniquely-encoded ultrasonic waves and detect the existence and location of the object.

An ultrasonic sensor 1000 has a transmission/reception processing circuit 100, and the transmission/reception processing circuit 100 has a burst signal transmission circuit 1 that generates and transmits burst signals S0, and a signal processing circuit 7 that processes reception signals received by a piezoelectric element 4. The signal processing circuit 7 verifies the reverberation frequency of the reverberation signals of ultrasonic signals (reception signals) reflected to the piezoelectric element 4 from a subject, and on the basis of the verified reverberation frequency and reverberation time of the reception signals, adjusts the frequency of the burst signals S0 to be substantially equal to the reverberation frequency, said burst signals being to be generated by the burst signal transmission circuit 1.

A platform operates in an environment with other platforms using active sensing. The platform includes an active sensing system configured to provide a point cloud associated with the environment. The point cloud is used to navigate the platform. The active sensing system includes a transmitter configured to provide pulses of electromagnetic energy in a light band or a radar band or sonic energy and a receiver configured to receive returns associated with the pulses striking one or more targets in the environment. The transmitter is configured to impose a code onto the pulses, and the receiver is configured to detect the code to determine when the pulses of light where transmitted or to determine a source of the pulses.

A method of detecting objects includes transmitting toward an object a first acoustic signal including a first set of pulses including a first number of pulses, and checking if a first echo signal resulting from reflection of the first acoustic signal is received with an intensity reaching an echo detection threshold. If the intensity of the first echo signal reaches the echo detection threshold, the distance to the object is calculated as a function of the time delay of the first echo signal. If the intensity of the first echo signal fails to reach the echo detection threshold, one or more further acoustic signals are transmitted including a set of pulses wherein the number of pulses is increased with respect to the number of pulses in said first acoustic signal.

Ultrasonic sensing systems and associated methods provide side-lobe reduction to improve the acoustic detection of small objects, the signature envelope peaks of which can otherwise be obscured by subsidiary envelope peaks in side lobes that result from residual correlation between a signal received by an ultrasonic transducer and a template signal corresponding to a burst signal emitted by the ultrasonic transducer. A shaping signal by which the amplitude of the burst signal can be varied with respect to time is taken into account in the template signal, and correlator circuitry correlates a signal derived from the ultrasonic transducer with the template signal to produce a correlated output exhibiting the desired side-lobe reduction. The distance from the transducer to the detected object can thereby be determined with enhanced accuracy and responsiveness.

An object detection device includes: a transducer having a vibrator transmitting and receiving an ultrasonic wave and configured to transmit a transmission signal encoded to be imparted with identification information and receive the transmission signal reflected by an object as a reception signal; a correlation processing unit acquiring a first correlation value corresponding to a degree of similarity between the identification information of the transmission and reception signals and to determine whether the reception signal to which the identification information having a predetermined level or higher degree of similarity with the identification information of the transmission signal is imparted has been received; and a detection unit detecting information about the object when determined that the reception signal to which the identification information having the predetermined level or higher degree of similarity is imparted has been received.

A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-component message for ensonifying multiple fans and deconstructs a corresponding message echo for use in analyzing the returns from each fan.