Abstract
The conventional method for measuring tidal current velocity generally employs current meters suspended, at predetermined depth, from buoys located at limited number of selected locations. Recently in Japan, the high industrial development and rapid harbour construction have brought demands for more detailed and synoptic surveys of current in straits and harbours. The aerial photogrammetric measurement of tidal current, adopted by the Coast and Geodetic Survey, U. S. A., for the first time, have given us some useful hints for our own development in tidal current measurement, which in turn gives answer to the above mentioned demands. This paper reports the principles and methods of photogrammetric measurement of tidal current survey, and the new techniques such as synchronized photography and vector analysis, developed by the authers. In next paper (part II), the results obtained by these methods applicated to Akashi Seto (Akashi strait), Japan will be reported.
