Dynamic RCS Estimation of Drone Using Method of Moments Ignoring Coupling Between Propellers

We proposed a method for quickly estimating the dynamic radar cross-section (RCS) of a drone in various motions to train a classifier. The method of moments (MoM) is used with far-field approximation and mesh-element rotation. In this method, first, the impedance and admittance matrices of a single propeller are generated only once. Next, instead of rotating propeller, the position information of the mesh elements is rotated using a Rodrigues 3D rotation matrix. Finally, by using the mirror-image symmetric characteristics of drone propellers and the far-field approximation, the backscattered field of multi-propeller can be computed from the superposition of the propeller individual backscattered fields. Dynamic RCS estimation was performed at 3 GHz and 9 GHz. In addition, dynamic RCS was converted to spectrogram and Cadence-velocity diagram (CVD). As a result, it was difficult to obtain the rotation frequency at 9 GHz, whereas it was easier to find the rotation frequency at 3 GHz.