HIGH-FREQUENCY RCS OF COMPLEX RADAR TARGETS IN REAL-TIME

This paper presents a new and original approach for computing the high -frequency radar cross section (RCS) of complex radar targets in real time with a 3-D graphics workstation. The aircraft is modeled with I-D EAS solid modeling software using a parametric surface approach. High- frequency RCS is obtained through physical optics (PO), method of equi valent currents (MEC), physical theory of diffraction (PTD), and imped ance boundary condition (IBC). This method is based on a new and origi nal implementation of high-frequency techniques which we have called g raphical electromagnetic computing (GRECO). A graphical processing app roach of an image of the target at the workstation screen is used to i dentify the surfaces of the target visible from the radar viewpoint an d obtain the unit normal at each point. High-frequency approximations to RCS prediction are then easily computed from the knowledge of the u nit normal at the illuminated surfaces of the target. The image of the target at the workstation screen (to be processed by GRECO) can be po tentially obtained in real time from the I-DEAS geometric model using the 3-D graphics hardware accelerator of the workstation. Therefore, C PU time for RCS prediction is spent only on the electromagnetic part o f the computation, while the more time consuming geometric model manip ulations are left to the graphics hardware. This hybrid graphic-electr omagnetic computing (GRECO) results in realtime RCS prediction for com plex radar targets.