METHOD FOR DETERMINING WIND SPEED OVER WATER SURFACE Russian patent published in 2017 - IPC G01P5/01 G01S17/95 

FIELD: measuring equipment.

SUBSTANCE: method for determining the wind speed over a water surface is proposed, in which more than two spatio-temporal images of a water surface are obtained from optical images obtained by means of more than two optical systems based on CCD photodiode lines, synchronized with one single master oscillator and mounted with different directions of sight in a given angular sector determined by the azimuth angle between the extreme CCD photodiode lines. Each CCD photodiode line records one-dimensional optical images with capturing the horizon line and a part of the sky at small viewing angles. Two images obtained from adjacent CCD photodiode lines are docked by distance. The propagation directions of wind gusts (the angles between the sight directions of adjacent CCD photodiode lines and the motion direction of the wind gust bands between adjacent CCD photodiode lines are determined) and the velocity of wind gusts for adjacent CCD photodiode lines are determined by the inclination angles of the wind gust bands on space-time images obtained by adjacent CCD photodiode lines and the known angle between the sight directions of adjacent CCD photodiode lines. The wind speed is determined over each point of the water surface in the sight direction of each CCD photodiode line from the known model dependence of the dispersion of wave slopes on the wind speed, taking into account the wind gust direction, and the value of the dispersion of wave slopes in the sight direction at each point of the water surface is obtained by solving the "conversion" problem of the dependence of the water surface brightness on the dispersion of the wave slopes with allowance for the angular distribution of the sky brightness. To solve the "conversion" problem, a comparison of the measured water surface brightness normalized to the brightness of the sky at the horizon, recorded in the optical image of the water surface, and the model (calculated) normalized water surface brightness is used at each point of the water surface in the sight direction of each CCD photodiode line. In the formula for the water surface brightness, either an analytical expression for the angular distribution of the sky brightness depending on the lighting conditions is used, or the angular distribution of the brightness of the sky and the water surface area near the horizon is used, recorded in the digital form, if it is necessary to achieve high spatial resolution on the water surface in the sight direction of CCD photodiode lines, or by means of two mutually calibrated cameras, the lenses of which are equipped with polaroids with vertically and horizontally located transmission axes, or by means of a single video camera, the lens of which, like the objectives of the CCD photodiode lines, is equipped with polaroids with either a vertical or a horizontally located transmission axis. In the CCD photodiode line, long-focus narrow-angle lenses are used, and in case of need to achieve a broad band of view - using the CCD photodiode lines themselves with wide-angle lenses mounted thereon and polaroids with a vertical or horizontally located transmission axis, mounted on the lenses.

EFFECT: increasing the accuracy of determining the wind speed.

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