Abstract: Information regarding shallow-water bathymetry holds substantial practical significance for marine resource exploitation and environmental conservation. Disturbances in the current field induced by topography give rise to patterns of surface convergence and divergence, which subsequently regulate the distribution of sea-surface roughness. These regulatory effects are then clearly reflected in high-resolution synthetic aperture radar (SAR) imagery. As a result, SAR images offer a viable approach for high-resolution inversion of pre-existing submarine topography. Owing to the scarcity of high-resolution ground-truth data, SAR bathymetry inversion based on deep learning mainly depends on simulated datasets for model training. This study leverages a full- chain SAR ocean imaging simulation model to facilitate the rapid generation of large-scale, high-precision simulated datasets under complex shallow-sea topographic conditions.The Taipingsha area in Jiangsu Province and the northeastern coastal waters of Hainan Island are selected as representative study sites. A comparative analysis is conducted between simulated and real SAR images acquired at three distinct time periods. Quantitative analysis reveals that the simulated images demonstrate a high degree of consistency with the real SAR images in terms of textural structure, brightness distribution, and spatial patterns. Specifically, the maximum structural similarity indices for the Taipingsha area and the northeastern coastal waters of Hainan Island reach 0.62 and 0.73 respectively. Both global and local analyses of the simulation results further validate the physical consistency and generalization ability of the simulation model across various topographic and hydrodynamic conditions. The constructed full-chain simulation model effectively reconstructs the entire physical process from underwater topography to SAR image formation, enabling forward simulation from bathymetric data to SAR imagery.

Key words: Underwater terrain inversion, Full-chain simulation, Wave action equation, Sea surface current field modulation