Disclosed is a LADCP and USBL combined observation device and a use method thereof. The device includes a cable winch system, a mounting frame, a LADCP system, a USBL beacon and a correction system. The LADCP system, the USBL beacon and the correction system can be mounted to the mounting frame by adopting a hardware support platform. The cable winch system can drive the LADCP system to deploy or recover along a vertical section. The LADCP system is used to obtain the current velocity of a single small profile, and the USBL beacon can locate the underwater position information, and the correction system can obtain data information in the seawater where the mounting frame is located, so as to calculate an absolute current velocity according to the velocity obtained by the LADCP system and the current data obtained by the correction system.

An acoustic air data system includes first and second acoustic transmitters, an array of acoustic receivers, and control circuitry. The array is positioned to receive first and second acoustic signals. The control circuitry determines time difference of arrival (TDOA) of the first and second acoustic signals. The control circuitry determines, for each of a first and second set of acoustic receiver pairs, a signal velocity of the first and second acoustic signals, respectively, based on a distance between an inner acoustic receiver and an outer acoustic receiver and a corresponding TDOA for each pair of acoustic receivers. The control circuitry estimates one or more of wind angle, speed of sound, Mach number, and true airspeed of the airflow about the exterior of the vehicle based on parameters of a best fit circle.

A body for an acoustic resonance fluid flow speed sensor or an acoustic resonance fluid flow sensor comprising such a body, the body comprising a reflector surface with at least one section that is more hydrophilic than a surrounding section of the reflector surface to promote movement of water from a centre toward an edge of the reflector surface.

A method of measuring the speed of a fluid comprising the following steps: generating a plurality of pseudorandom frequencies (fus_n); for each pseudorandom frequency (fus_n), emitting ultrasound signals into the fluid to travel along a path of defined length; receiving the ultrasound signals; for each received ultrasound signal, producing a travel time measurement, so as to generate for each pseudorandom frequency (fus_n) a predefined number of travel time measurements; for each pseudorandom frequency (fus_n), evaluating the accuracy of the measurements; for evaluating the speed of the fluid, making use of the measurements produced for the pseudorandom frequency that presents the greatest accuracy.

An underwater acoustic receiver apparatus (100) comprises an acoustic reflector (102, 104, 106, 108) and an acoustic device (110, 114, 116, 118) aimed at the acoustic reflector (102, 104, 106, 108). The acoustic reflector (102, 104, 106, 108) is disposed at a predetermined distance and orientation relative to the acoustic device (110, 114, 116, 118).

A wave generator for an ultrasonic air data system can be configured to collect data derived from a flow of air in a downstream direction. The wave generator can include an ultrasonic wave source configured to output ultrasonic waves from a first end and a wave shaper connected to the first end of the ultrasonic wave source. The wave shaper can be configured to focus the ultrasonic waves into an area downstream from the ultrasonic wave source bounded by a first plane parallel to the downstream direction and a second plane orthogonal to the first plane.

A wave generator for an ultrasonic air data system can be configured to collect data derived from a flow of air in a downstream direction. The wave generator can include an ultrasonic wave source configured to output ultrasonic waves from a first end and a wave shaper connected to the first end of the ultrasonic wave source. The wave shaper can be configured to focus the ultrasonic waves into an area downstream from the ultrasonic wave source bounded by a first plane parallel to the downstream direction and a second plane orthogonal to the first plane.

In one embodiment, a system includes a vehicle, one or more probes coupled to the vehicle, and a controller. The vehicle is operable to traverse a distance. The one or more probes are operable to measure wind pressure and generate one or more wind pressure measurements. The controller is operable to receive the one or more wind pressure measurements from the one or more probes, determine a wind angle relative to the vehicle using the one or more wind pressure measurements, and determine a wind speed relative to the vehicle using the one or more wind pressure measurements and the wind angle.

A measurement apparatus 100 includes a measurement unit 10 to propagate an ultrasonic wave in a medium 98 that flows inside a pipe 99 and to receive the ultrasonic wave, a difference calculating section 23a to calculate a difference signal obtained by taking a difference in waveforms of reception signals at least between two received ultrasonic waves, and an identifying section 23d to identify a reception timing of transmission of an ultrasonic wave based on a target signal component included in the difference signal. According to the identification of the reception timing based on the target signal component included in the difference signal, a flow velocity of the medium 98 can be measured precisely by using the reception timing.

A method, apparatus, and system according to which first and second waveguides are adapted to be connected to a pipe and first and second transducers are adapted to be connected to the first and second waveguides, respectively, and to exchange ultrasonic wave signals through the first and second waveguides, the pipe, and a fluid flowing in the pipe. A temperature of the fluid flowing in the pipe exceeds 600° C. The first and second waveguides are configured to, and each have a shape to: (i) insulate the first and second transducers from the pipe, and (ii) permit propagation of the ultrasonic wave signals between the pipe and the first and second transducers, respectively, while maintaining an acoustic attenuation through the first and second waveguides at an acceptable level.