A driving support apparatus according to the present disclosure includes a memory and a hardware processor coupled to the memory and a sound wave sensor. The hardware processor is configured to select, as a transmission and reception scheme, either a pulse scheme or a spread spectrum modulation scheme, and control the sound wave sensor with the selected transmission and reception scheme. When the spread spectrum modulation scheme is selected as the transmission and reception scheme, the hardware processor causes the sound wave sensor to successively transmit and receive sound waves by using the spread spectrum modulation scheme.

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 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.

An underwater detection apparatus, which includes a transmission transducer, a reception transducer, and a motor, is provided. The transmission transducer is configured to transmit a transmission wave within a given transmission fan-shaped space, the transmission fan-shaped space having a first transmission width in a given first plane and a second transmission width in a second plane perpendicular to the first plane. The reception transducer is configured to receive a reflection wave of the transmission wave within a given reception fan-shaped space, the reception fan-shaped space having a first reception width in the first plane and a second reception width in the second plane, the second reception width being narrower than the second transmission width, and in the second plane, one of a pair of edges of the transmission fan-shaped space being within the reception fan-shaped space. The motor is configured to rotate the transmission and the reception fan-shaped spaces.

An underwater detection apparatus, which includes a transmission transducer, a reception transducer, and a motor, is provided. The transmission transducer is configured to transmit a transmission wave within a given transmission fan-shaped space, the transmission fan-shaped space having a first transmission width in a given first plane and a second transmission width in a second plane perpendicular to the first plane. The reception transducer is configured to receive a reflection wave of the transmission wave within a given reception fan-shaped space, the reception fan-shaped space having a first reception width in the first plane and a second reception width in the second plane, the second reception width being narrower than the second transmission width, and in the second plane, one of a pair of edges of the transmission fan-shaped space being within the reception fan-shaped space. The motor is configured to rotate the transmission and the reception fan-shaped spaces.

Embodiments of the present disclosure describe an efficient O(n log n) method that implements the Inverse Chirp Z-Transform (ICZT). This transform is the inverse of the well-known forward Chirp Z-Transform (CZT), which generalizes the fast Fourier transform (FFT) by allowing the sampling points to fall on a logarithmic spiral contour instead of the unit circle. Thus, the ICZT can be viewed as a generalization of the inverse fast Fourier transform (IFFT).

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.

A method comprising: providing an autonomous vehicle (AV) with a first estimated position of a target; directing the AV to travel toward the first estimated position at a constant velocity; receiving echo signals of transmitted sonar signals, the echo signals indicating a range and an azimuth of the target; determining a depth difference of the AV and the target based on the received echo signals, the depth difference being determined based on changes to the range and azimuth of the target over time; and in response to a depth difference existing, re-directing the AV toward a second estimated position of the target generated from the depth difference.

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 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.