Wave Flume Measurement Using Image Analysis

Wave observation represented water surface elevation at a reference point is basic and essential data for ocean and coastal engineering that is mostly measured with traditional wave gauges, for instance capacitance, resistance and conductivity types. Therefore, accuracy and exactness are the most important aspects of data acquisition systems. In this study, we focus on the development of image processing techniques for wave measurement in a wave flume as a tool to replace traditional wave gauges, which are complicated to use, costly and intrusive. Recently, image processing techniques have been developed for utilization in various tasks. The main factors that influence the accuracy of these techniques are image quality, algorithm performance and exact calibration. Image processing techniques based on edge detection algorithms were used to measure waves in the laboratory with a camera. The experimental results showed the agreement of water surface elevation from both measurement methods. The average wave height and average wave period of regular wave obtained from the zero up-crossing analysis were different by less than 10% and 1% respectively compared with traditional wave gauges. Moreover, this algorithm can also measure irregular waves in hydraulic laboratories as well. Hence, this approach is a new, alternative tool for use in wave flume measurement, with good results.