Electromagnetic Scattering from a Ship at Sea
Abstract
A simplified model is developed to analyze the high frequency electromagnetic scattering from a ship at sea. The ship is modelled by an elliptic cylinder to represent the superstructure, superimposed on a portion of an elliptic cone to represent the full structure. The Geometrical Theory of Diffraction in conjunction with an efficient specular point tracking algorithm is employed to calculate the scattering from this ship model. The sea surface is replaced by a rectangular path model which divides the antenna illuminated sea surface into square sub-areas. The scattering from each sub-area is represented by a polarization transforming reflection coefficient derived from the bistatic radar cross-section of the patch. In general, there are three basic scattering mechanisms that contribute to the total signature as the radar system traverses the ship target. These are the direct back-scattered signal from the sea surface (the so-called clutter component), the ship-sea double-bounce interaction term, and the signature scattered by the ship alone. A number of signatures, for various trajectories, antenna patterns, and polarizations have been calculated, and are used to illustrate the effect of the aspect angle of the trajectory, the curvature of the hull, etc. on the detectability of the ship in clutter, and the relations between the position of the ship and the position of the peak signature voltage.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1978
- Accession Number
- ADA081118
Entities
People
- John Huang
- William H. Peake
Organizations
- Ohio State University