Development of Measuring System for Wave Heigtht Distribution

利用可视化的流场图像进行测量的技术，即所谓的图像测量，能够在没有任何常规探头的情况下测量瞬时流场。近年来，速度场的测量系统有了很大的发展，并提出了一些可用于实际测量的先进系统，作者提出了另一种利用空气-水之间光散射差的图像测量技术，除激光器和VTR摄像机外，不需要任何特殊仪器。光在水中的散射强度与在空气中的散射强度有很大的不同，自由表面轮廓作为图像中亮区和暗区的边界。它是可视化的薄激光片照明。该系统是为测量拖曳水池中的波高分布而研制的。特别是在匀速前进和规则波情况下，都是如此。

Measurement technique using a visualized flow image, the so-called image measurement, enable to measure instantaneous flow field without any conventional probe. The measurement systems for velocity field have been remarkably developed recently, and advanced systems to be applied on practical measurement are proposed.The authors have developed another image measuring technique using the difference of light scattering between air water, without any particular instruments except for the laser and VTR camera. The strength of light scattering in water is much different from one in air, and the free surface profile is obtained as the boundary of bright and dark area in the image. It is visualized on the thin laser sheet illumination. The system is developed here to measure the wave height distribution in towing tank. Particularly, not only in the case of advanced with uniform speed but also in regular wave.