WAVE DIRECTION CALCULATING METHOD OF BUOY-TYPE WAVE HEIGHT METER

PROBLEM TO BE SOLVED: To solve a problem in wave direction measurement by a GPS buoy wherein a wave direction cannot be stably measured at 360° by the covariance of the horizontal moving speed of the buoy and the vertical position of the buoy due to noncoincidence between the motion of water particles and the motion of the buoy. SOLUTION: The method comprises carrying out wave direction calculation by dividing it into two calculations and combining the results thereof. First calculation is to determine the vibrating (reciprocating) direction (180° wave direction) of water particles. The vibrating direction of water particles can be determined by a method of carrying out coordinate conversion and determining the direction in which primary or secondary moment (power) is maximum. Second calculation is to determine the traveling direction of wave and the 360° wave direction. In the case of the buoy type, the 360° wave direction value of water particles by covariance is not stable but its code has stability. The code of the covariance value in the 180° wave direction obtained in the first method is obtained to determine the traveling direction. The stable 360° wave direction measurement of the buoy type is attained by utilizing the advantages of the two methods. COPYRIGHT: (C)2009,JPO&INPIT