SAR Image Generation of Ocean Surface Using Time-Divided Velocity Bunching Model

Abstract

An efficient synthetic aperture radar (SAR) image formulation based on the velocity-bunching model is proposed for a large SAR image integration time. A time-varying ocean surface is generated based on the semi-empirical spectrum proposed by Fung and Lee. The ocean surface is discretized using the facet model, in which the normalized radar cross-section is calculated using the combined model of the Kirchhoff approximation and the small perturbation method. The velocity-bunching model can be used only when the integration time is sufficiently shorter than the ocean wave periods. To overcome this limitation, we propose a time-divided velocity-bunching model applicable to a large integration time. The SAR image and its spectrum computed by the proposed model are numerically verified by the comparing the results using the time-dependent model in various scenarios. The computational complexities between the time-dependent and the time-divided velocity-bunching models are compared.

Keywords

• Ocean Backscatterer
• Synthetic Aperture Radar Image
• Time-Dependent Model
• Velocity-Bunching Model