1：Experimental Design and Method Selection:

The study uses a gridded approach for automatic processing of SAR data to derive bathymetry. It involves the use of the dispersion relation for surface water waves, with wavelength and wave period as inputs. The method includes automatic pre-filtering, Fast Fourier Transformation (FFT) for wavelength retrieval, and an iterative process for wave period determination using root mean square deviation (RMSD) analysis against database depths.

2：Sample Selection and Data Sources:

Data from the TerraSAR-X satellite in StripMap mode was used, specifically a scene acquired over the Channel Islands on 2010-03-31. Bathymetry data from public databases like EMODnet and GEBCO were used for comparison and initial values.

3：Bathymetry data from public databases like EMODnet and GEBCO were used for comparison and initial values. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: TerraSAR-X satellite data (Multi-Look Ground Range Detected products with pixel spacing of 1.25 m in StripMap mode), FFT for spectral analysis, and computational tools for iterative calculations.

4：25 m in StripMap mode), FFT for spectral analysis, and computational tools for iterative calculations. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The SAR scene is read, calibrated, and divided into subscenes. Subscenes are pre-filtered, FFT is applied to derive wavelengths, and an iterative process is used to find the optimal wave period by comparing calculated depths with database depths via RMSD. The optimal period is then used to compute the final bathymetry map.

5：Data Analysis Methods:

RMSD analysis is used to evaluate deviations between derived and database depths. Statistical methods are applied to filter errors and ensure accuracy.