Manmade Target Scattering Structure Null-Pol Recognition and Application

Target's optimal polarization is the fundamental theory of radar polarization. Null-Pol, also called Co-Pol Null, is one of the significant polarization states, through which other optimal polarization states can be derived. Null-Pol theory is widely applied in polarization reception match, contrast enhancement and so on. This paper revealed the advantage of Null-Pol theory in manmade target scattering structure recognition for the first time. The complex polarization ratio plane and polarization response characteristics were combined and the Null-Pol 3D response patterns were represented, which can reveal the difference of canonical scattering structures. Then, the Null-Pol scattering structure recognition method of manmade targets is proposed. The scattering centers are extracted from radar images. The scattering structure type can be identified by matching the Null-Pol response characteristic vectors with canonical scatters. Through the analysis of electromagnetic computation data of manmade targets, the proposed Null-Pol scattering structure recognition method can identify the scattering structure types of manmade targets. Especially, the results of symmetric targets have better performance than Cameron decomposition, which is more consistent with target's actual scattering structure types.