An embodiment provides a device for measuring a fluid parameter of fluid flow in a channel, including: a transmitter; at least one receiver; a processor operatively coupled to the at least one transmitter and the at least one receiver; a memory device that stores instructions executable by the processor to: transmit, using the transmitter, directed energy carrying a signal toward a surface of a fluid in a fluid channel, so as to produce one or more reflections from the fluid surface; detect, by the at least one receiver, one or more received signals associated with the one or more reflections so produced; determine, based upon a measurement beam comprising characteristics of the transmitted and received signals, one or more fluid parameters to be measured using a processor of the device; and associate, using a processor of the device, the one or more fluid parameters with a channel segment. Other embodiments are described and claimed.

An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

This method includes emitting, by an emitter at an emitting depth, moved along an axis, at least one incident sound wave at an emitting frequency, receiving a first sound wave reflected by a first reflective object at a first depth and a second sound wave reflected by a second reflective object at a second depth, greater than the first depth, providing a first velocity at the first depth, and determining a second velocity of the sound waves at the second depth, from the frequencies of the first and second reflected sound waves, the emitting frequency and the first velocity.

This method includes emitting, by an emitter at an emitting depth, moved along an axis, at least one incident sound wave at an emitting frequency, receiving a first sound wave reflected by a first reflective object at a first depth and a second sound wave reflected by a second reflective object at a second depth, greater than the first depth, providing a first velocity at the first depth, and determining a second velocity of the sound waves at the second depth, from the frequencies of the first and second reflected sound waves, the emitting frequency and the first velocity.

A method for recognizing a noise represented in a receive signal of an ultrasonic sensor. A characteristic spectrum of the noise is compared with a noise spectrum of the receive signal, the noise spectrum including at least two noise levels determined in different frequency bands of the receive signal.

A method for recognizing a noise represented in a receive signal of an ultrasonic sensor. A characteristic spectrum of the noise is compared with a noise spectrum of the receive signal, the noise spectrum including at least two noise levels determined in different frequency bands of the receive signal.

A method for identifying a road condition of a road. A piece of road condition information representing the road condition is determined using a noise level detected by at least one ultrasonic sensor of a vehicle and a bottom echo detected from a road surface in the area of the vehicle.

A method for identifying a road condition of a road. A piece of road condition information representing the road condition is determined using a noise level detected by at least one ultrasonic sensor of a vehicle and a bottom echo detected from a road surface in the area of the vehicle.

An air data sensor can include an acoustic transmitter configured to output an acoustic signal into an airflow and a plurality of acoustic transducers configured to receive the acoustic signal output by the acoustic transducer. The air data sensor can also include a light source configured to output a light beam into the airflow, and a light receiver configured to receive scattered light from the light beam. The light source and the light receiver can be bistatic such that a measurement zone is formed away from the air data sensor.