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

• Published in: Journal of Electromagnetic Engineering and Science Vol. 19; no. 2; pp. 82 - 88
• Main Authors: Rim, Jae-Won, Koh, Il-Suek
• Format: Journal Article
• Language: English
• Published: 한국전자파학회JEES 01.04.2019; The Korean Institute of Electromagnetic Engineering and Science; 한국전자파학회
• Subjects: Ocean Backscatterer; Synthetic Aperture Radar Image; Time-Dependent Model; Velocity-Bunching Model; 전자/정보통신공학; Time-Dependent Model; Velocity-Bunching Model; Ocean Backscatterer; Synthetic Aperture Radar Image
• ISSN: 2671-7255; 2234-8409; 2671-7263; 2234-8395
• DOI: 10.26866/JEES.2019.19.2.82

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.