An Enhanced Adaptive Ray-Tracing Technique for Monostatic RCS Prediction of Curved Targets

An enhanced adaptive ray-tracing technique is proposed for fast monostatic RCS prediction of curved targets with multiple reflections. The method performs nonuniform ray tracing guided by the phase variation rate of the induced surface currents, allowing a significantly reduced ray-tube density in slowly varying regions to improve efficiency. The curvature of the ray-tube wavefront is preserved, and the incident directions on the wavefront are parameterized by locally approximating the wavefront using a spherical triangle, from which the maximum phase variation rate and the corresponding maximum sampling rate are derived. A divergence factor is further incorporated to correct the induced-current amplitude, and the scattered field is evaluated using analytical PO integrals. Numerical results demonstrate substantial improvements in both computational efficiency and accuracy for complex curved geometries.