A method for tracking moving particles in a fluid. The method includes illuminating the moving particles with an illumination sequence of patterns generated by a light projector; measuring with a single camera light intensities reflected by the moving particles; calculating, based on the measured light intensity, digital coordinates (x′, y′, z′) of the moving particles; determining a mapping function f that maps the digital coordinates (x′, y′, z′) of the moving particles to physical coordinates (x, y, z) of the moving particles; and calculating the physical coordinates (x, y, z) of the moving particles based on the mapping function f. The illumination sequence of patterns is generated with a single wavelength, and light emitted by the projector is perpendicular to light received by the single camera.

A structured-light-velocimetry method includes extracting one or more bursts from a time-varying signal generated by detecting scattered light from a tracer particle passing through a structured optical beam; fitting each of the one or more bursts to a multi-variable model to extract a plurality of fitted parameters; and executing a machine-learning model with the plurality of fitted parameters to predict an angular velocity of the tracer particle.

An optical measurement device is provided with: a light source that irradiates, with light, a measurement object which has a fluid flowing thereinside; a light receiving unit which, upon receipt of scattered light from the measurement object irradiated with light, outputs a light reception signal according to the intensity of the scattered light; a disturbance generation unit which generates a disturbance signal for causing oscillation of a drive current to be supplied to the light source; and an adjustment unit which adjust the drive current on the basis of the result of a comparison between the disturbance signal and a signal generated on the basis of the light reception signal.

An optical measurement device is provided with: a light source that irradiates, with light, a measurement object which has a fluid flowing thereinside; a light receiving unit which, upon receipt of scattered light from the measurement object irradiated with light, outputs a light reception signal according to the intensity of the scattered light; a disturbance generation unit which generates a disturbance signal for causing oscillation of a drive current to be supplied to the light source; and an adjustment unit which adjust the drive current on the basis of the result of a comparison between the disturbance signal and a signal generated on the basis of the light reception signal.

A fluid measurement device includes sensor elements that are arranged around a pipe in which a fluid containing a scatterer flows and include each of a light source, a light receiver, and a partition structure for shading between the light source and the light receiver, a signal processor that processes the signals obtained from the light that has been received and photoelectrically converted by the light receivers, and a calculator that calculates at least one of a flow velocity and a flow rate using the signals processed by the signal process unit. The light source and the light receiver in each of the sensor elements are arranged in proximity along the pipe axis direction of the pipe so as to have a reverse positional relationship to the light source and the light receiver in the adjacent sensor elements.

According to an example aspect of the present invention, there is provided a sensor comprising at least one strut configured to be coupled to a surface of an object at a first end of the strut, a structure connected to a second end of the at least one strut, wherein the structure is V-shaped, U-shaped, curved or arched and configured to be coupled to the surface at both ends, a plurality of cavities positioned along the structure on both sides of the at least one strut, and a plurality of fibre-optic pressure transducers, wherein a single fibre-optic pressure transducer is arranged within each of the cavities, and wherein the sensor is configured such that at least some of the fibre-optic pressure transducers are arranged at different distances from the surface of the object.

A non-invasive microwave measuring device (01) is for calculating the flow rate of a fluid. The device (01) includes a non-invasive microwave fluid velocity measuring device (03) having a patch antenna or horn antenna to generate a microwave signal (14) that is transmitted at a specific elevation angle α towards the fluid surface (16) and to receive the reflected microwave signal (15) from the fluid surface (16) with a doppler shift frequency. The measuring device (03) is suspended from a drone (02) by a suspension system (04). The suspension system (04) eliminates vibration noise generated by the drone (02). At least one vibration sensor eliminates false velocity readings. At least one angle sensor compensates for Pitch, Roll and Yaw from the drone (02) that influence the fluid surface velocity measurement.

A non-invasive microwave measuring device (01) is for calculating the flow rate of a fluid. The device (01) includes a non-invasive microwave fluid velocity measuring device (03) having a patch antenna or horn antenna to generate a microwave signal (14) that is transmitted at a specific elevation angle α towards the fluid surface (16) and to receive the reflected microwave signal (15) from the fluid surface (16) with a doppler shift frequency. The measuring device (03) is suspended from a drone (02) by a suspension system (04). The suspension system (04) eliminates vibration noise generated by the drone (02). At least one vibration sensor eliminates false velocity readings. At least one angle sensor compensates for Pitch, Roll and Yaw from the drone (02) that influence the fluid surface velocity measurement.

A method for determining a particle velocity of an aerosol by means of an aerosol measuring device. Aerosol particles flow through a measuring cell and are illuminated with an electromagnetic beam. The scattered light is registered and detected by a sensor. The temporal signal durations of the scattered light signals are determined, and the particle velocity of the aerosol is determined on the basis of the signal durations. Furthermore, the invention provides an aerosol measuring device designed to carry out the steps of the method according to the invention for determining the particle velocity of an aerosol. In addition, a computer program having program code means is provided, which computer program is configured to carry out the steps of the method according to the invention.

A method for determining a particle velocity of an aerosol by means of an aerosol measuring device. Aerosol particles flow through a measuring cell and are illuminated with an electromagnetic beam. The scattered light is registered and detected by a sensor. The temporal signal durations of the scattered light signals are determined, and the particle velocity of the aerosol is determined on the basis of the signal durations. Furthermore, the invention provides an aerosol measuring device designed to carry out the steps of the method according to the invention for determining the particle velocity of an aerosol. In addition, a computer program having program code means is provided, which computer program is configured to carry out the steps of the method according to the invention.