Analysis of the Fetch Dependency of the Slope of Wind-Water Waves

In this thesis mean square slope has been calculated from slope images which were recorded by the Imaging Slope Gauge (ISG) at the annular wind-wave tank Aeolotron in Heidelberg. The calculations have been realized using three different methods, which are, (i) calculation of the variance, (ii) integration of the slope power spectrum and (iii) fitting the probability distribution function of slope with a model function. The resulting values have been compared to each other and to the existing live evaluation of the ISG for a wide range of wind and fetch conditions. Also the fetch dependence of mean square slope has been analyzed, which obtains information about the evolution of a wave field. Additionally the slope images have been separated with the use of band pass filters into slope images of gravity waves and capillary waves. By separating gravity from capillary waves it was possible to analyze their slope probability distribution functions individually.