The Polar Coordinate Transformation Numerical Steepest Descent Path Method for Calculating Physical Optical Scattering Field of Quadric Concave or Convex Surfaces

In this letter, the polar coordinate transformation numerical steepest descent path (PCT-NSDP) method is proposed to calculate the physical optics (PO) scattered field from concave or convex quadratic surfaces. In the proposed method, only three triangles integral domains are calculated, which avoids the complicated decomposition in the former NSDP methods. The PCT-NSDP method has a closed-form formula of the contribution of PO stationary phase point. Therefore, the calculation time can be much smaller. Moreover, the workload is frequency-independent. The numerical examples of the radar cross section of a quadratic convex surface demonstrate the high accuracy and efficiency of the PCT-NSDP method.