This invention relates to a method of improving performance of a SODAR system adapted to locate discontinuities in the atmosphere by transmitting pulse compression signals such as a plurality of acoustic chirps, the method comprising: transmitting one or more acoustic chirps; receiving one or more acoustic echoes of the transmitted chirps; processing the acoustic echoes to provide an indication of the discontinuities in the atmosphere, thereby providing a wind shear profile; processing the wind shear profile to correct systematic Doppler errors associated with the acoustic echoes by: subtracting a first measured wind speed from the wind shear profile; and adding a second measured wind speed to the wind shear profile.

A survey system including a multibeam echo sounder having a projector array and a hydrophone array uses a multi-component message to ensonify one or more fans to estimate a Doppler velocity.

A device and method used to image conduits, such as pipes, wellbores and tubulars, with imaging sensors, such as cameras and ultrasound arrays. The speed and location of the device are determined using one or more speed sensor modules. Images are then registered to more precise axial locations along the conduit than are normally possible using wireline encoders or other methods. The conduit may be visualized to proper scale for improved analysis of defects.

A method is for determining a speed of an object based on an ultrasonic pulse. The method includes emitting the ultrasonic pulse using a first ultrasonic transducer. The ultrasonic pulse having a defined signal profile. The method further includes receiving an ultrasonic signal using a second ultrasonic transducer, calculating a cross-correlation, with respect to frequency, of the ultrasonic signal with a filter signal which at least partially correlates with the defined signal profile, and determining a frequency shift between the filter signal and the received ultrasonic signal using a result of the calculated cross-correlation. The method also includes determining the speed of the object which reflected the emitted ultrasonic pulse using the determined frequency shift.

In an ultrasonic detection system that uses frequency-modulation or phase-modulation coding to distinguish emitted bursts from multiple transducers, a receiver associated with a transducer uses peak search, peak buffer, and peak rank stages in one or more receiver signal processing paths to identify valid received ultrasonic signal envelope peaks in correlator outputs. The peak rank stage can support different modes respectively designed to handle one code, two or more codes, or two or more codes with support for Doppler frequency shift detection. Valid peak information (e.g., amplitude and time) can be reported to a central controller and/or stored locally in a fusion stage to generate more intelligent information for targets or obstacles using peaks from multiple bursts.

A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

An unmanned aerial vehicle comprising a velocity sensing system is provided. The velocity sensing system comprises a transmitter configured to transmit a first acoustic signal having at least a first frequency and a receiver, configured to detect a second acoustic signal comprising the first acoustic signal after it has been reflected from a reflective surface. The velocity sensing system is configured to determine from the second acoustic signal a second frequency, said second frequency comprising the first frequency after having undergone a Doppler shift; and to use the first and second frequencies to determine a velocity at which the unmanned aerial vehicle is travelling relative to the reflective surface.

Ultrasonic ranging systems and methods that emit coded bursts and correlate transduced acoustical echoes of the bursts with a receive template characterizing a burst code to determine time-of-flight information use receive templates of time-variable length to improve short-range object detection. The template length is based on a time index measured from the start of the burst emission. The detection can account for a dead zone of transducer ringing following a burst. A time-variable gain that is also based on the time index can be applied to the correlated signal. The length and gain can be adjusted with reduced temporal frequency to reduce computation cost.

A method and a device examine an environment of a vehicle by analyzing echo signals generated by reflection of transmitted ultrasonic signals at an object. Two different ultrasonic burst signals are transmitted in a same direction and into a same area of the environment. Timely offset echo signals are created at an object by reflection of the two ultrasonic burst signals. The two echo signals are evaluated to determine different parameters of an object. The distance of the object is calculated based on the echo signal of the ultrasonic burst signal with the lower number of ultrasonic pulses. Based on the echo signal of the ultrasonic burst signal with the higher number of ultrasonic pulses, the velocity can be calculated at which the vehicle and the object move relative to each other in the direction of transmission of both ultrasonic burst signals or opposite thereto.

An in-air sonar system is provided for determining location and velocity information of objects in an environment. The in-air sonar system includes at least two emitters configured to emit respective sound signals into the environment; at least two receivers configured to receive sound signals from the environment; and a processing unit configured to perform: obtaining, from the receivers, respective received sound signals comprising the emitted sound signal reflected from objects in the environment; calculating, from the respective received sound signals, respective velocity-dependent range maps; deriving, from the calculated velocity-dependent range maps and the spatial diversity of the receivers, a velocity-dependent range-direction map comprising range information as a function of a received direction; determining therefrom a location of the respective objects; and extracting, from the velocity-dependent range maps and the spatial diversity of the receivers, a velocity of the respective objects based on the determined location.