| 摘要 |
PURPOSE:To measure highly accurately snow depth by providing the titled instrument with a light source for irradiating light to a snowfall face, a camera for photographing the snowfall face and a data processor for finding out the snowfall depth from information photographed by the camera. CONSTITUTION:A linear light source 1 is directed to the snowfall face and an irradiation line on the snow face is equal to the edge of a section obtained by cutting the snowfall by the surface of ground and an angle theta. The center axis of photographing of the TV camera is rectangularly intersected with the linear light source 1. A dotted line (a) shows the irradiation line due to the linear light source 1 on the ground surface before snow falling and may be moved up to a full line (b) as the result of snow falling. Thereby, snow depth H can be detected by measuring the displacement of the position on a screen formed by the lines (a) and (b). The snow depth can be measured on the basis of equation I in the data processor 3. In the equation, (d) is the moved distance (m) of the linear light source, theta is the irradiating angle (rad) of the linear light source 1 to the ground surface and the snow depth H is obtained by (m).
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