Principles and Methods of Radar Super-Resolution Based on Instantaneous Polarization Response.

Compared to the steady-state part of the extended target echo, few scholars have paid enough attention to the echo establishment and disappearance part. They contain abundant target information but have not been fully explored and utilized. Since the pulse duration of both parts is typically short, they can be considered as instantaneous processes. Polarization is an inherent property of electromagnetic waves, which can bring information gain to the analysis of the echo instantaneous part. The objective of this study is to utilize the instantaneous polarization response (IPR) of the echo to achieve super-resolution for two targets with different polarization scattering characteristics. It is analyzed that when two target echoes are “equal-amplitude and opposite-phase,” echo decoupling can be achieved, which is the precondition for achieving range super-resolution. Making full use of the polarization information is instrumental in achieving the echo with “equal-amplitude and opposite-phase.” A trihedral and a dihedral are selected to verify the effectiveness of the proposed method. Multiple sets of measured data show that the two target echoes do have the instantaneous part. When the signal-to-noise ratio (SNR) of the echo data is about 6–7 dB, the range super-resolution and range estimation of the two targets are achieved by using the edge threshold detector.