2018 Volume 24 Pages 41-46
In order to improve the applicability and operational efficiency of image-based noncontact river flow measurement using a video camera, we developed an auxiliary recording device which can accurately calculate the vertical imaging angle by combining high precision inclinometers. With this method, an oblique image can be ortho-rectified without using reference marks at the time of observation. Therefore, it is possible to omit the labor of measuring the reference marks to easily perform field measurement. Furthermore, we developed a web-based application using this device. In this system, image geometry correction and LSPIV analysis are performed on the web server, so it becomes possible to check the measurement results on the site. As an application to the river flows observation, we examined the change in the flow velocity due to the Asahi Bridge over the Shinano River and successfully demonstrated the influence range of wake flow by the bridge piers.
