A Novel PE/FDTD Hybrid Model for Predicting Echo Signals of Radar Targets in Large-Scale Complex Environments

Ju Feng,Yuping Shang,Cheng Liao,Haijing Zhou,Dongmin Zhang,Xiaochuan Deng

doi:10.1109/access.2020.2972365

Abstract

The prediction of radar target echo signal in a large-scale complex environment is of great significance in target detection, radar design and other applications. In this paper, a novel PE/FDTD hybrid model is proposed to predict monostatic radar target echo signals in large-scale complex environments. The target echo signal can be regarded as the output response of the transmitted signal which passes through a linear time invariant system composed of complex environment and target. The transport function of the complex environment is computed by the parabolic equation (PE) method and the scattering characteristics of the target are calculated by finite difference time domain method (FDTD). The combination of PE and FDTD is realized through the system response function. In combination with the “stop-go” method, the prediction of moving target echo signal is realized. In addition, the error of combining PE with FDTD is analyzed, and the result shows that the error is less than 0.1% when the target distance is more than 10km. Additional numerical examples are given to demonstrate the correctness of the method in semi-space, rain, fog and atmospheric duct environments. The calculated results are compared with those of theoretical method, time-domain shooting and bouncing ray (TDSBR), multi-level fast multi-pole method (MLFMM) and waveguide mode theory, and good agreement among them is observed. Finally, the simulation analysis of the missile echo signal in the mixed sea-land environment with surface duct is carried out. The simulation results show that this model can be used to predict the echo signal of airborne targets in a large-scale complex environment. It is a promising option for multi-scale computing involving radar target and large-scale environment.

Highlights

Radar target echo signal prediction is widely used in ocean detection [1], target recognition [2], SAR imaging [3], long-range radar surveillance [4], missile fuze [5] and other fields
This paper presents a novel parabolic equation (PE)/finite difference time domain method (FDTD) hybrid model for predicting monostatic radar target echo signals in a large-scale complex environment
The combination of PE and FDTD method is realized through the system response function, which greatly simplifies the complexity of the combination algorithm

Summary

INTRODUCTION

Radar target echo signal prediction is widely used in ocean detection [1], target recognition [2], SAR imaging [3], long-range radar surveillance [4], missile fuze [5] and other fields. In [18], time domain parabolic equation (TDPE) method is proposed based on SSFT-PE, which is the most effective signal prediction method in large-scale complex environment. SSFT-PE algorithm has huge advantages in efficiency compared with FDTD, MoM and other full wave algorithms in solving the problem of radio wave propagation in complex environment, it is a challenge to calculate the scattering characteristics of the target accurately due to the limitations of the algorithm itself [19]. In [21], the hybrid method of FDTD and PE algorithm has been proposed to solve the problem of radio wave propagation in key areas of large-scale environment. This paper presents a novel PE/FDTD hybrid model for predicting monostatic radar target echo signals in a large-scale complex environment.

METHODS AND FORMULATIONS

PARABOLIC EQUATION METHOD

TARGET FAR-FIELD CHARACTERISTIC FUNCTION

MOVING TARGET ECHO PREDICTION MODEL

PREDICTION OF TARGET ECHO SIGNAL IN COMPLEX ENVIRONMENT

Findings

CONCLUSION