A Method of Measuring One-Dimensional River Surface Flow Using Spatiotemporal Images

Abstract

In this paper, a new image analysis method for measuring river surface flow was developed. In the presented method, some shortcomings of the large-scale-PIV, the previously developed image analysis technique by the authors, were significantly improved by using all video frames and constructing a spatiotemporal image for a searching line. Measurement of velocity in the direction of the searching line was performed by measuring an image intensity gradient of striped pattern appeared in the spatiotemporal image. By using the new method, it became possible to obtain velocity in a far field from a viewing location with a small depression angle. It was shown that the presented method demonstrates a favorable performance when applied to the actual river flow measurement.