Provided is a system for adjusting an ultrasonic sensor threshold value according to a vehicle height on the basis of a ground wave model. The system includes a vehicle height detection unit configured to detect a vehicle height, a ground wave modeling unit configured to model a ground wave model by matching a ground waveform start delay time and a threshold value for each vehicle height detected by the vehicle height detection unit and provide the modeled ground wave model, and an ultrasonic sensor configured to store the ground wave model and a ground waveform reference threshold value measured at a lowest vehicle height of a vehicle and compensate a lowest vehicle height threshold value according to the current vehicle height using a ground waveform start delay time calculated according to the detected vehicle height.

Methods and apparatus are described for implementing a coding scheme on ultrasound signals received by a plurality of ultrasonic transducers. The coding, and subsequent decoding, may allow for multiple ultrasonic transducers to be operated in a receive mode simultaneously while still differentiating the contribution of the individual ultrasonic transducers. Improved signal characteristics may result, including improved signal-to-noise ratio (SNR).

An object detection apparatus includes a transmitting portion configured to transmit a transmission wave, a receiving portion configured to receive a reception wave based on the transmission wave which returned, an estimation portion configured to estimate an amount of frequency transition between the transmission wave and the reception wave on the basis of a result of a frequency analysis, a correction portion configured to correct the reception wave to obtain consistency of frequencies with the transmission wave on the basis of an estimation result of the estimation portion, and a detection portion configured to detect information related to the object on the basis of a relation between the transmission wave and the corrected reception wave corrected by the correction portion.

A method of performing distance estimation between a first recording device at a first location and a second recording device at a second location includes: estimating acoustic relative transfer function (RTF) between the first recording device and the second recording device for a sound signal, e.g., by applying an improved proportionate normalized least mean square (IPNLMS) filter; and estimating the distance between the first recording device and the second recording device based on the RTF. The at least one acoustic feature extracted from the RTF estimated between the first recording device and the second recording device includes at least one of clarity index, direct-to-reverberant ratio (DRR), and reverberation time. A distributed-gradient-boosting algorithm with regression trees is used in combination with signal-to-reverberation ratio (SRR) and the at least one acoustic feature extracted from the RTF to estimate the distance between the first recording device and the second recording device.

A system is provided for imaging an underwater environment. The system includes one or more arrays of transducer elements. Each array is operated at a fixed phase shift and varies in frequency so as to beamform multiple sonar return beams of a first range of angles and a second range of angles. The arrays can be oriented to cover the gap in sonar coverage for other arrays to create a continuous arc of sonar coverage. Accordingly, a 2D live sonar image can be formed. One or more of the multiple sonar return beams facing downwardly can be selected and used to form downward sonar images that anglers are used to, without requiring separate transducer elements. Fish arches formed using multiple sonar return beams can be positioned appropriately within a high resolution downward sonar image to form a desirable combined sonar image.

Disclosed is a method for determining a difference in depth or a lateral distance in relation to the vertical between two points of an underwater environment, in particular by measuring a propagation time of a sound wave. The determination is based on a single-layer model of the environment in which the wave is supposed to propagate in a straight line along an effective propagation direction, at a mean velocity that is independent of the propagation direction. Also disclosed is a method for determining the profile of the mean velocity based on the measurements of differences in depths per se, a determination of the local velocity profile over the variation interval of the sounded depths, and a related sonar system.

An obstacle detection sensor includes: a controller configured to determine a detection condition of an obstacle on a road; a distance sensor unit configured to acquire distance information by oscillating a vibration wave and receiving a reflected wave of the oscillated vibration wave; a communication unit configured to communicate with an outside to acquire road surface information; and a storage unit configured to store detection relationship information for identifying the obstacle based on the distance information, in which the controller compares the detection relationship information read from the storage unit with the distance information and the road surface information acquired from the distance sensor unit and the communication unit to determine the detection condition.

An apparatus for correcting an input signal is configured for receiving the input signal, the received input signal comprising a series of input values. The apparatus is configured for matching a series of template values to the series of input values by warping the series of template values and the series of input values relatively to each other so as to assign one or more template values to one or more input values, wherein the series of template values represents an approximation of a noise signal that is expected to be comprised in the input signal. The apparatus is configured for obtaining a series of corrected input values based on a mismatch between the input values and their respective assigned template values. The apparatus is configured for providing a corrected signal based on the series of corrected input values.

Ultrasonic ranging state management for a UAV is described. A transducer transmits an ultrasonic signal and receives an ultrasonic response thereto using a gain value. A noise floor estimation mechanism determines a noise floor estimate. A state mechanism sets an ultrasonic ranging state used by the transducer to a first ultrasonic ranging state. The transducer transmits an ultrasonic signal and responsively receive an ultrasonic response to the ultrasonic signal using a gain value according to the noise floor estimate. The state mechanism processes the ultrasonic response to determine whether to determine a new noise floor estimate, adjust the gain value used by the transducer, or change the ultrasonic ranging state of the UAV to a second ultrasonic ranging state. The configurations of the first and second ultrasonic ranging states differ as to, for example, power and gain levels used by the transducer to receive ultrasonic responses.

An ultrasonic sensing system includes a comparator, an analog-to-digital converter (ADC) coupled to the comparator, and a processor coupled to the comparator and the ADC. The comparator is configured to compare an input signal with a triggering value and trigger proximity measurement in response to an amplitude of the input signal being greater than the triggering value. The ADC is configured to convert the input signal to a digital signal. The processor is configured to, in response to the proximity measurement being triggered, determine a peak time point when a peak amplitude is received based on the digital signal and calculate a distance based on the peak time point. The peak time point is different from a time point when the proximity measurement is triggered.