DETERMINATION METHOD OF UNDERWATER SOUND WAVE PROPAGATION PATH (SOUND RAY) FUNCTION CONSIDERING EARTH SPHERE, DETERMINATION METHOD OF SOUND RAY DISTANCE FUNCTION, DETERMINATION METHOD OF SOUND RAY PROPAGATION TIME FUNCTION, DETERMINATION METHOD OF UNDERWATER SOUND SPEED VERTICAL DISTRIBUTION FUNCTION, SOUND RAY FUNCTION DETERMINATION PROGRAM AND SOUND RAY FUNCTION DETERMINATION COMPUTER SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a method for determining a sound ray function considering the earth sphere.SOLUTION: The invention is configured to: divide an object region into plural fan-shaped minute zones W, W, of the earth center angle Δφ, so that, the object region can be handled as a sphere similar to the earth; apply a sine theorem about a triangle formed of the earth center G and the passage points h, h, when passage points of a sound ray on boundaries between the respective minute zones, are h, h, for determining incident angles α, αand outgoing angles β, β; and sequentially calculate depths y, yof the sound ray on the passage points h, h. Then, Fourier transformation is performed on the depths y,y, for acquiring a function of the depth y in which the earth center angle φ is a variable: (sound ray function)y=f(φ). Since the minute zones are made the fan-shape, so that, deflection of the sound ray in the boundaries between the minute zones is handled as sea of the sphere, so that, the sound ray function with high accuracy is acquired. Since the sound ray regulated by the function is acquired, so that y to an optional φ can be calculated at high speed.SELECTED DRAWING: Figure 5