An efficient algorithm to compute the RCS of UAV swarmbased on spherical harmonic transform

Abstract

ABSTRACT It is time-consuming to simulate the unmanned aerial vehicle (UAV) swarm by the Multi-Level Fast Multipole Algorithm (MLFMA). This paper proposes a method to accelerate the simulation by neglecting the coupling among UAVs and computing the scattered field by Spherical Harmonic Transform (SHT). The key point is evaluating the scattered electric field of a UAV on an eccentric sphere by changing the order of summation of the spherical harmonics and then accelerating the summation by Fast Fourier Transform (FFT). The example of a swarm of 6 UAVs shows that the bistatic Radar Cross Section (RCS) obtained by the proposed method is in good agreement with the RCS obtained by MLFMA, and the proposed method requires 4.76 times less memory and is 10.93 times faster than MLFMA.