Echo-Level SAR Imaging Simulation of Wakes Excited by a Submerged Body

Area of Science:

• Oceanography
• Electromagnetics
• Fluid Dynamics

Background:

• Submerged body wakes significantly impact ocean dynamics and are detectable via Synthetic Aperture Radar (SAR).
• Understanding SAR imaging of these wakes requires integrating hydrodynamic and electromagnetic scattering principles.

Purpose of the Study:

• To develop a numerical simulation method for SAR imaging of submerged body wakes.
• To analyze the influence of navigation parameters and sea surface conditions on wake characteristics in SAR images.

Main Methods:

• Utilized Computational Fluid Dynamics (CFD) for simulating wake hydrodynamics and wind waves.
• Computed electromagnetic scattering characteristics of wakes under varying conditions.
• Established SAR raw echo signals and generated simulated SAR images using the Range-Doppler (RD) algorithm.

Main Results:

• CFD effectively simulates wake characteristics influenced by submerged body velocity.
• Wake backscattering features are dependent on the orientation relative to the radar line of sight.
• Wake detectability in SAR images diminishes at lower submerged body speeds or under specific wind conditions, where wakes can be masked by sea surface background.

Conclusions:

• The integrated numerical simulation method provides a valuable tool for understanding SAR imaging of submerged body wakes.
• Wake detectability in SAR is sensitive to both the body's motion and environmental factors like wind speed.
• Further research can refine SAR-based detection of submerged objects by considering these hydrodynamic and electromagnetic interactions.