Abstract:

Aiming at the difficulties in determining the order of the geometric theory of diffraction (GTD) model, distinguishing multiple scattering centers in low resolution, huge computation and escaping from the local supreme value, a new method for parameter estimation of GTD model combining RELAX and improved particle swarm optimization (PSO) is proposed. The iterative strategy of RELAX is applied to avoid the order determination of model, and the algorithm stably and efficiently converges at the global optimum value by giving the initial value of range parameters through imaging process and introducing the mutation mechanism. The super resolution is achieved by examining whether one scattering center or more exists in a resolution unit. The feasibility and effectiveness of the proposed method are verified by simulation and measurement.