A Fast Algorithm for Establishing 3-D Scattering Center Model for Ship Targets over Sea Surface Using the Shooting and Bouncing Ray Technique

Abstract

Fast construction of the 3-D scattering centers of ship targets on the sea surface is important for many radar applications, including the fast signature prediction, feature extraction, and automatic recognition of targets. Combining the “four-path” model for target-surface coupling scattering with modified Fresnel reflection coefficient model in the stochastic sea surface and ray tube integration method, we propose a 3-D image formation method for ship-surface compound targets. Using the CLEAN technique on 3-D image, we develop a fast algorithm for establishing 3-D scattering center model for ship targets on the sea surface. Because this algorithm realizes 3D imaging of targets at a single frequency and single aspect angle, and adopts simplified surface model to avoid the need to construct a large number of surface elements, the computational efficiency of the proposed alogrithm is greatly increased to meet the needs of practical engineering applications. Simulation experiments of a typical ship target show that the proposed algorithm can increase the speed by four orders of magnitude under typical conditions, as compared with the traditional FFT-based 3D imaging method. We validate the accuracy of this algorithm by comparing reconstructed 1-D range profiles and ISAR images obtain by the scattering center model with the ones that are directly simulated.

Keywords

• Ship target over sea surface
• 3-D scattering center model
• “Four Path” model
• Ray tube Integration
• CLEAN algorithm