Implementation of the algorithm of spectral analysis of waves in bathymetry of coastal waters of Oman Sea

Abstract

Understanding the characteristics of the seabed and ocean plays a crucial role in coastal management and engineering, exploration of coastal resources, navigation, research on tides and biodiversity, planning for the construction of marine structures and aquaculture. Mapping of shallow coastal areas is necessary to protect the ship in the navigation area. Remote sensing techniques can be an alternative method to reduce the cost of seabed hydrography. Synthetic Aperture Radar (SAR) images are active remote sensing images that are not sensitive to climatic conditions and are able to provide two-dimensional images of the sea surface with global coverage.

This research was conducted by implementing the algorithm of the spectral analysis of swell waves on Sentinel-1 satellite images from coastal waters of Oman Sea, and bathymetry map of the coastal areas was prepared. This method is based on the breaking and changes in the wavelength of swell waves in coastal waters and can measure depth in waters with medium depth. Two-dimensional Fourier analysis was used to determine the wavelength of long waves, and the accuracy of wave peak calculation was increased by applying a frequency filter. Two methods were used to extract the periodicity of swell waves.

After the statistical comparison of the results with the field data, the bathymetry accuracy was 1.125 m, the mean absolute error was 0.811, the mean relative error was 5.051%, and the correlation was 0.853, which confirms the suitability of this method in coastal waters.