9results about "Measuring open water depth" patented technology

The application discloses a water laser echo signal processing model training method and a water depth measuring method, and belongs to the field of laser radar water depth detection. The method comprises the following steps: obtaining multiple groups of underwater laser echo signals and preprocessing to obtain an underwater laser echo signal dataset; the preprocessing comprises the following steps: after normalizing each group of underwater laser echo signals, labeling the data points located on the rising edge of the water surface waveform as water surface points, labeling the data located on the falling edge of the water bottom waveform as water bottom points, and labeling the remaining data points as noise points; building a classification model for predicting the types of the data points in the underwater laser echo signal and training the classification model by using the underwater laser echo signal dataset to obtain an underwater laser echo signal processing model. The application can accurately identify the data points located on the rising edge of the water surface waveform and the falling edge of the water bottom waveform in a complex environment, and provides a reliable basis for calculating the time difference between the water bottom points and the water surface points, thereby improving the measuring accuracy of the water depth.

Device (1) for measuring an environment (2) by measuring the time of flight of a laser beam (3) reflected therefrom from a low-scattering first medium (4), comprising: a laser transmitter (5) for emitting the laser beam (3) at a target (8) in the environment (2), which is preceded by a higher-scattering second medium (9), a receiver (13) with a detection device (14) for receiving the laser beam (3) reflected from the environment (2), and an evaluation unit (16) connected to the laser transmitter (5) and the receiver (13) for determining the time of flight of the laser beam (3), wherein the receiver (5) separates a first beam part (19) reflected at the target (8) from a second beam part (23) reflected at the boundary (18) between the first and second medium (4, 9) and generates separate output signals (24i) from them, which the evaluation unit (16) evaluates separately.

The application discloses a method for retrieving water depth by using airborne laser radar sea surface point cloud. The method carries out pretreatment on the original point cloud data obtained by the airborne laser radar, and extracts the sea surface signal point cloud; carries out two-dimensional Fourier transform on the sea surface signal point cloud, and extracts the wave length and wave direction information of the sea surface at different positions; establishes the relationship between the wave length, period and water depth of the sea surface based on the linear wave theory, estimates the wave period through the wave characteristics of the deep water area; and calculates the water depth result of the near-shore water area through the dispersion relationship by using the tracked near-shore wave length and wave direction information. Since the laser energy is rapidly attenuated by turbid water, the traditional laser depth radar cannot directly detect the water bottom signal in the turbid water area, the sea surface point cloud data obtained by the airborne laser radar is used to calculate the sea surface wave parameters and then retrieve the water depth, and the method is not affected by water quality, and can effectively fill the underwater topographic data blank in the turbid water area.

The present disclosure relates to a method for multispectral remote sensing stochastic optimal ratio-logarithmic bathymetry inversion. The method addresses an issue that a water body signal is typically below 5%. The method comprehensively considers influences of a solar spectrum, an upward total scattering, a solar zenith angle, a total global transmittance, a direct irradiance, and a total spherical albedo. The method constructs an atmospheric coupled radiometric calibration correction model to correct atmospheric and water surface reflectance. The method corrects a tide height through a divided difference interpolation tide height correction model. The method accurately extracts a water body range by combining an FNDWI normalized difference water index. The method effectively extracts sub-datasets through a stochastic optimal model. The method optimizes model parameters of a ratio-logarithmic model using an extreme gradient boosting manner. The method obtains an optimized optimal ratio-logarithmic model for bathymetry inversion to achieve bathymetry inversion. A comparison is made between inversion results of the optimized optimal ratio-logarithmic model for bathymetry inversion and inversion results of a Stumpf model. The R2 accuracy of the bathymetry inversion by the optimal ratio-logarithmic model for bathymetry inversion is improved by 0.592, and an RMSE is improved by 0.841 m.

The present disclosure is related to an unmanned aerial vehicle-mounted continuous variable-frequency blue-green laser radar for water depth survey, including a blue-green light variable-frequency laser, a laser power supply driver, an encoding motor, a reflective optical wedge, a reflector, a big lens, a small lens, a balanced light detection module, a high-speed laser acquisition processor, an IMU module, an RTK module, a 4G module, a controller, a 4G antenna, a server, a mobile phone terminal and the like according to a characteristic that continuous variable-frequency blue-green laser generates frequency change when encountering a water surface and a water bottom, convolution and fast Fourier transform and a time-frequency correspondence. The laser radar is small in size, light in weight and suitable for an unmanned aerial vehicle to survey a water depth rapidly and precisely, achieves a millimeter-level precision, and realizes 0-10 m water depth survey.

The present disclosure relates to a technology for measuring water depth by using a drone, and provides an apparatus and a method for measuring water depth, in which: a drone flies to any one of a plurality of locations in a preset area and hovers above the water surface; a storage unit is mounted on the lower part of the drone and stores measured water depth; a unit for controlling length is mounted on the lower part of the storage unit and connected to the upper part of a water depth measurement sensor to control the length between the storage unit and the water depth measurement sensor; and a signal is emitted into the water via the water depth measurement sensor floating on the water surface, the round-trip time of the signal reflected from the bottom and received is measured, and water depth is measured on the basis of the round-trip time and the moving speed of the signal.

The application discloses a rigorous photon counting mechanism laser radar underwater sounding point coordinate calculation method, mainly including the following steps: (1) analyzing the structure of the photon counting laser radar scanning system, establishing the geometric relationship model of the incidence angle, the azimuth angle and the mirror normal vector of the laser reflected light on the water surface; (2) constructing the coordinate calculation model of the laser water surface incidence point in the laser scanning reference coordinate system; (3) proposing a constant light speed light ray tracing model in the underwater layer, and constructing the coordinate calculation model of the underwater sounding point in the laser scanning reference coordinate system; (4) establishing the relationship model of the laser scanning reference coordinate system and the WGS84 space rectangular coordinate system, and returning the laser underwater sounding point coordinates to the WGS84 space rectangular coordinate system. Through the above steps, the accurate measurement of the underwater laser radar sounding point coordinates can be realized.

A polar vessel is disclosed. The polar vessel includes: a keel protruding from the lower part of the vessel; and an echo sounder mounted on the keel, configured to transmit ultrasonic pulses toward the seabed, receive ultrasonic pulses reflected back from the seabed, and calculate the depth of the seabed based on the time required for the ultrasonic pulses to return.

Aspects of the present invention relate to a control system (400) for a trailer manoeuvring system of a vehicle (100), the control system comprising one or more processors (310) collectively configured to receive (530, 540), from a sensing device (445), a wirelessly transmitted level signal (447) indicative of at least one of a pitch or roll angle of a trailer, receive (520), from a user interface (410), a levelling request signal, and activate a levelling movement mode in dependence on the levelling request signal, wherein, in the levelling movement mode, the one or more processors are collectively configured to output (740, 840) a movement signal (426) to cause the vehicle (100) to move in a longitudinal direction in dependence on the level signal being indicative of the at least one of the pitch or roll angle of the trailer being within a predetermined range.