An electronic device 1 comprises: a transmitting antenna configured to transmit transmitted waves; a receiving antenna configured to receive reflected waves obtained by reflection of the transmitted waves; and a controller. The controller detects, based on transmitted signals transmitted as the transmitted waves and received signals received as the reflected waves, an object reflecting the transmitted waves. The controller determines frequencies of transmitted waves to be transmitted from the transmitting antenna based on results of receiving, from the receiving antenna, each of reflected waves obtained by reflection of a plurality of transmitted waves with different frequencies transmitted from the transmitting antenna.

A method of determining a distance to a discontinuity within an object may include the steps of: a) generating a continuous, frequency modulated input signal having a predetermined frequency range and a frequency ramping speed using a signal generator and splitting the input signal into at least a test signal and a reference signal; b) generating an input sound wave based on the test signal and continuously introducing the input sound wave into the object using a transmitter and simultaneously receiving a reflected sound wave reflected by a discontinuity within the object and generating a corresponding return signal using a receiver; c) determining a frequency difference value based on a comparison of the reference signal and the return signal using a controller; and d) automatically determining a distance from the transmitter to the discontinuity within the object based on at least the frequency difference value and the frequency ramping speed.

A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-signal message and deconstructs a corresponding multi-signal echo to substantially simultaneously perform multiple survey missions.

A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-signal message and deconstructs a corresponding multi-signal echo to substantially simultaneously perform multiple survey missions.

Methods and devices for detecting movement of an object includes: receiving a first set of output signal values and a second set of output signal values from a sound wave receiver, each output signal value in the first set and the second set being representative of amplitude of an acoustic signal reflected from the object; determining, based on the received first set and second set, a difference set including one or more difference values, each of the one or more difference values being representative of a difference between a first output signal value in the first set and a second output signal value in the second set; determining whether the difference set satisfies a predetermined condition based on whether each difference value of the difference set has a magnitude exceeding a predetermined threshold; and outputting a motion detection signal if the difference set satisfies the predetermined condition.

Methods and devices for detecting movement of an object includes: receiving a first set of output signal values and a second set of output signal values from a sound wave receiver, each output signal value in the first set and the second set being representative of amplitude of an acoustic signal reflected from the object; determining, based on the received first set and second set, a difference set including one or more difference values, each of the one or more difference values being representative of a difference between a first output signal value in the first set and a second output signal value in the second set; determining whether the difference set satisfies a predetermined condition based on whether each difference value of the difference set has a magnitude exceeding a predetermined threshold; and outputting a motion detection signal if the difference set satisfies the predetermined condition.

A reference signal distribution system is disclosed. The reference signal distribution system can include a power splitter to create, from a frequency-divided reference signal, a counterclockwise divided reference signal and a clockwise divided reference signal. The reference signal distribution system can include a distribution ring to provide the counterclockwise divided reference signal to a ring tap, and provide the clockwise divided reference signal to the ring tap. The reference signal distribution system can include a ring tap to produce a phase synchronization signal based the counterclockwise divided reference signal and the clockwise divided reference signal. The reference signal distribution system can include an analog regenerative frequency divider to produce a common phase reference signal based in part on the phase synchronization signal.

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.

A frequency modulation continuous wave (FMCW)-based system includes an emitter to transmit at least one linearly modulated wave of radiation to a scene and a receiver to receive a reflection of the transmitted wave from one or multiple objects located at different locations in the scene. The system interferes a copy of the wave outputted by the emitter with the reflection of the transmitted wave received by the receiver to produce a beat signal with spectrum peaks corresponding to reflections from the different locations at the scene. The beat signal is distorted due to the non-linearity of the modulation. The system includes a processor to detect a number of spectrum peaks in the distorted beat signal and, only in response to detecting multiple spectrum peaks, jointly determine coefficients of a basis function approximating the non-linearity of the modulation and distances to the different locations at the scene having the objects causing the reflection resulting in the spectrum peaks in the distorted beat signal.