Practical Illumination Uncertainty Assessment i-n Ground-Based Radar Measurements

The models governing ground-bounce illumination have been well understood for decades. Previously referenced work examined the application of these models to three-dimensional geometries, and showed that illumination variation is a spatially dependent function of frequency. Illumination variation requires knowledge of the target´s geometry and scattering characteristics in order to evaluate uncertainty. This paper leverages that work and further develops a short-time Fourier transform (STFT) method to extract frequency-domain scattering characteristics directly from target data. By utilizing at least two antenna heights in two separate measurements, ground-bounce geometries allow for useful target-feature characterization. This enables an assessment of spatial target uncertainty in the image domain, as well as for RCS; it further shows promise for illumination-error mitigation. This paper demonstrates this potential in simulation to support measurements collected at the National RCS Test Facility (NRTF), Holleman AFB, NM.