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.

An ocean current measurement method, includes: acquiring three-dimensional coordinates measured by four GNSS (Global Navigation Satellite System) positioning modules on the surface drifting buoy and attitude data of the surface drifting buoy measured by an attitude sensor; correcting the three-dimensional coordinates measured by the four GNSS positioning modules based on the attitude data; optimizing the corrected three-dimensional coordinates of the four GNSS positioning modules according to the mounting positions; converting the optimized three-dimensional coordinates of the four GNSS positioning modules into latitude and longitude coordinates; and calculating coordinates of the surface drifting buoy, an instantaneous flow velocity and flow direction of ocean current and sea surface elevation through the latitude and longitude coordinates of the four GNSS positioning modules. The coordinates with higher precision can be obtained, and the flow velocity, flow direction and sea surface elevation of the sea area where the buoy is located can be measured.

A tidal current information display device for a movable body includes a position measurement module to detect a position of the movable body, a geographical information selection module to determine geographic information to be displayed on a display screen based on the detected position, a tidal current information receiving module to receive and store tidal current information based on the detected position, a tidal current information display module to generate display data for displaying a first graphical user interface (GUI) for displaying the tidal current information corresponding to a predetermined position on the geographic information displayed on the display screen, and a voyage time calculation module to calculate an estimated time for the movable body to reach the predetermined position. The first GUI is configured for showing at least one of: the estimated time and a direction and speed of a tidal current at the estimated time.

Described here are systems and methods that utilize visual imagery and an optical flow-based computer vision algorithm to measure river velocity in streams or other flowing bodies of water. The systems and methods described in the present disclosure overcome the barriers of conventional flow measurement techniques by providing a fast, non-intrusive, remote method to measure peak flows.

Surface elements, such as protrusions, are provided for use on the surface of flow-following apparatuses, such as surface drifters or subsurface drogues, to enhance the hydrodynamic properties of the apparatus and enhance their capabilities to follow fluid motion. The protrusions may comprise helical strakes or splitter plates for optimizing the drag-to-inertia ratio of the flow-following apparatus, with the goal to enhance their flow-following capabilities. In some embodiments, the flow-following apparatus has a generally axisymmetric body shape, such as having a cylindrical, spherical or oblong shape. The flow-following apparatus may further comprise a position tracking device to track flow motion such as ocean currents.

A prediction portion predicts states including a water level of the wave at a prediction subject location. In a case in which inputs of the flow velocity in a line-of-sight direction of the wave at each observation location have been received, an estimation portion estimates states of waves including the water level thereof at the prediction subject location. The estimation of the states is based on a difference between the flow velocity in a line-of-sight direction of the wave at each input observation location, and the flow velocity in a line-of-sight direction of the wave at each input observation location obtained by converting states of the wave using an observation matrix. A determination portion causes the predictions of the states and the estimation of the states to be repeated until predetermined conditions have been satisfied.

Disclosed is a system for automatically measuring a discharge in real time based on a CCTV image. The system includes: a water depth measurement device filtering water depth data measured by a measurement means with a local linear regression-based bivariate scatterplot smoothing technique through flexible bandwidth application to calculate the water depth of a stream; an image acquisition device acquiring a continuous image of a flow speed measurement side of the stream; an image analysis PC using an image of the image acquisition device to measure the surface flow speed in real time and receiving a measured water depth from the water depth measurement device to measure the discharge in real time with cross-section data; and a discharge calculation and management server for transmitting and displaying a real-time discharge measurement result based on a web.

A method of identifying a rip current that includes receiving an image comprising a body of water, and identifying, in the image an estimated location of a rip current associated with the body of water, wherein the identification comprises a plurality of displayed vertices based on least one of a rip length or a rip width. The method may include digitizing the estimated location of the rip current, the estimated location having highest, lower, and no confidence boundaries. The method may include generating, based on the digitized estimated location, a set of fuzzy-set scheme labels for one or more pixels in the image based on a respective confidence boundary, where the fuzzy-set scheme labels are based on a pixel interpolation associated with the lower confidence boundary, and generating, based on the generated fuzzy-set scheme labels, a refined digitizing of the estimated location of the rip current.

Disclosed is a system for automatically measuring a discharge in real time based on a CCTV image. The system includes: a water depth measurement device filtering water depth data measured by a measurement means with a local linear regression-based bivariate scatterplot smoothing technique through flexible bandwidth application to calculate the water depth of a stream; an image acquisition device acquiring a continuous image of a flow speed measurement side of the stream; an image analysis PC using an image of the image acquisition device to measure the surface flow speed in real time and receiving a measured water depth from the water depth measurement device to measure the discharge in real time with cross-section data; and a discharge calculation and management server for transmitting and displaying a real-time discharge measurement result based on a web.

An inundation depth prediction device includes: a flow speed value acquiring unit that acquires a flow speed value on the sea surface; and an inundation depth predicting unit that predicts an inundation depth on the ground by inputting the flow speed value acquired by the flow speed value acquiring unit to a learned inundation depth prediction model used for predicting the inundation depth on the ground from the flow speed value on the sea surface.