Simulation of target responses to high frequency ultra wideband radar signals using the physical optics impulse response

Abstract

High-frequency ultrawideband radar signals are constructed by modulating a microwave or millimeter wave carrier with a broad bandwidth signal with the percentage bandwidth of the modulating signal being typically more than 20% of the carrier frequency. The wideband properties of the signal render the single-number radar cross section (RCS) inadequate for target response simulations. Instead, a characteristic function describing the response of the target to the waveform must be obtained in either the time or frequency domain. A first approximation to the temporal impulse response of a target can be obtained from physical optics (PO). The target's response can then be obtained by convolving the signal with the temporal impulse response of the target. A computational method for obtaining a PO signal response is described, and the results are compared to analytic responses for some primitive volumes (flat plate, cone, sphere).