A Novel Method for Radar Echo Simulation based on Fast-Constructed Database

This paper presents a novel method for fast calculation of radar echo in near-field regions after the equivalent source has been computed by method of moments (MoM). An easy-to-access near-field database (NFDB) is established, which is built on the auxiliary tetrahedral meshes surrounding the near-field regions of interest. The near-fields calculation (NFC) of arbitrary observation points can be expressed explicitly via the NF-DB. An efficient matrix compression scheme named random sampling-based butterfly factorization (RS-BF) is proposed to speed up the construction of NFDB. With this approach, each group of O(N) elements in the database can be calculated through one fast matrix-vector multiplication operation that has a computational complexity below O(Nlog N). The proposed method can avoid time-consuming point-by-point NFC of the traditional methods. Several numerical examples are presented to demonstrate the accuracy and efficiency of this method. In particular, the echo simulation of a missile-target encounter example is presented to illustrate its capability for practical applications.