A method of measuring tides and inland water levels is provided. The method comprises a computer receiving a first measurement of an angle formed by a first ray comprising a vertical fixed piling and a second ray formed by a downward sloping ramp of known length, a lower end of the ramp contacting a surface of a dock float and the surface representing a plane contacting the fixed piling at a 90-degree angle at a first meeting point. The computer then calculates, based on the first measurement, based on the ramp length, and based on the 90-degree angle, a first distance from the first meeting point to a vertex of the angle. The computer later receives a second measurement of the angle, wherein the plane meets the piling at a second meeting point. The computer calculates a second distance and expressing a difference between two distances as tidal change.

The present disclosure relates to a method for measuring a water level by using a UAV and virtual water control points and a method for generating 3D water surface spatial information, and a UAV used therefor. According to an embodiment, an UAV for a water surface survey includes: a position measurement unit configured to receive a GPS signal and to obtain position information of the UAV; a distance measurement unit including a plurality of laser measurement devices configured to project lasers toward the water surface; and a controller configured to calculate a moving distance of the UAV, based on measurement values of the position measurement unit and the distance measurement unit.

The present disclosure discloses a tropical instability wave early warning method based on temporal-spatial cross-scale attention fusion, including performing cross-scale spatial map fusion on the multi-scale feature maps by a bilateral local attention mechanism, calculating a prediction loss by the global feature description map, and combining the prediction loss and the regularization loss for optimization training of neural networks; predicting a sea surface temperature at a moment T based on the optimally trained neural networks, selecting data at K moments before the moment T and inputting the data into the optimally trained neural networks, outputting a predicted value of tropical instability waves by the optimally trained neural networks, and drawing a temporal-spatial image of the tropical instability waves by associating the predicted value with coordinates, so as to achieve early warning of the tropical instability waves. The device includes a processor and a memory.

A method and a device for determining and displaying a flyaway distance for a rotorcraft in the event of an engine of the rotorcraft failing, and while taking account of the height of waves being overflown by the rotorcraft. The method includes a first determination for determining a flyaway distance of the rotorcraft in the event of a failure of an engine and under current flying conditions, a second determination for determining a maximum altitude of the waves being overflown by the rotorcraft and displaying the flyaway distance and the maximum altitude on a display instrument of the rotorcraft indicating the relative height of the rotorcraft or else its altitude. A safety margin is preferably added to the maximum altitude of the waves, or else to the flyaway distance of the rotorcraft.

An experimental system comprises a water level indicator, a data processing module, and an experimental simulator. The water level indicator is connected to the data processing module, and the water level indicator is mounted nearby the experimental simulator when in use. The experimental simulator comprises several experimental units. Each experimental unit comprises a first pipe, a second pipe, and a third pipe, wherein the first pipe perpendicularly communicates with the second pipe, a check valve which allows water to flow out but allows no water to flow in is connected to the water outlet of the second pipe, and the third pipe perpendicularly communicates with the second pipe and is parallel to the first pipe. The heights of the third pipes of the several experimental units are in a decreasing or increasing order.

The present invention relates to a method allowing short-term prediction of the wave motion (force, elevation, . . . ), from a time series of past wave measurements. The prediction method according to the invention is based on the estimation of the variable coefficients of an autoregressive model while allowing multi-step minimization, that is over a horizon of several time steps in the future, of the prediction error.

A method of determining the draft of a vessel comprising the steps of: measuring the draft of the vessel using at least one optical imaging device to provide optical draft measurement data; measuring the draft of the vessel using elevation data provided by at least one GNSS or GPS device so as to provide elevation draft measurement data; and using the elevation draft measurement data and the optical draft measurement data to determine the draft of the vessel.

The present application relates to a method for selecting a wave height threshold, based on a target location, original wave height samples are acquired, and a wave height threshold interval are obtained; combined with wave height threshold and based on GPD and specified return period, a design wave height Hs.sub.i,j corresponding to each threshold within the wave height threshold interval is calculated according to the sample wave height values which are greater that the threshold; a difference is calculated to obtain a stable threshold interval, and a threshold within the stable threshold interval is selected as a reasonable threshold for design wave height estimation. In this method, the stability of estimated values can be determined directly and objectively to realize wave height threshold selection.

An experimental system comprises a water level indicator, a data processing module, and an experimental simulator. The water level indicator is connected to the data processing module, and the water level indicator is mounted nearby the experimental simulator when in use. The experimental simulator comprises several experimental units. Each experimental unit comprises a first pipe, a second pipe, and a third pipe, wherein the first pipe perpendicularly communicates with the second pipe, a check valve which allows water to flow out but allows no water to flow in is connected to the water outlet of the second pipe, and the third pipe perpendicularly communicates with the second pipe and is parallel to the first pipe. The heights of the third pipes of the several experimental units are in a decreasing or increasing order.

The present invention relates to profiler systems and methods for observing and sensing aspects of a body of water at a plurality of depths. A water profiler is disclosed comprising, generally, a vessel body connected to an external mooring cable via an attachment means, a drive means for maneuvering the vessel body longitudinally about the mooring cable; an articulating mechanism; and a sensor array capable of measuring a parameter for study wherein the vessel body is capable of articulating about the mooring cable. In alternate embodiments, the articulation allows the vessel body to be placed in relation with the three dimensional current such that at least one sensor is positioned into the current so as to sample or measure undisturbed water. In alternate embodiments, hydrofoils or wings are mounted to the vessel body that can be manipulated to harness the current force and maneuver the vessel body.