Synthetic Aperture Imaging of Dispersive Targets

We introduce a dispersive point target model based on scattering by a particle in the far-field. The synthetic aperture imaging problem is then expanded to identify these targets and recover their locations and frequency dependent reflectivities. We show that Kirchhoff migration (KM) is able to identify dispersive point targets in an imaging region. However, KM predicts target locations that are shifted in range from their true locations. We derive an estimate for this range shift for a single target. We also show that because of this range shift we cannot recover the complex-valued frequency dependent reflectivity, but we can recover its absolute value and hence the radar cross-section (RCS) of the target. Simulation results show that we can detect, recover the approximate location, and recover the RCS for dispersive point targets thereby opening opportunities to classifying important differences between multiple targets such as their sizes or material compositions.

Automated summary

In this study, we propose a dispersive point target model based on scattering and develop a synthetic aperture imaging method to identify and recover the positions and frequency dependent reflectivities of these targets. Results show that we can detect, recover the approximate locations, and acquire the radar cross-section of dispersive point targets, providing opportunities to classify important differences between multiple targets.