Abstract
In case of discharge measuring of a river or traffic researching in streets by aerial photographs, it needs to know precise time at which photograph was taken so that we may calculate an exact speed of moving target. But it is impossible to know one by the way of photograpging a watch as it does in popular.
So, we had developed a“Recording system of photographing time for an aerial camera”in Kokusai Aerial Surveys Co., Ltd.. The outline of this paper had already presented on the 9th May 1971 in J. S. P. meeting.
