Multiple RFI Sources Location Method Combining Two-Dimensional ESPRIT DOA Estimation and Particle Swarm Optimization for Spaceborne SAR

Junfei Yu,Bing Sun,Liying Xu,Jingwen Li,Yuming Jiang

doi:10.3390/rs13061207

Abstract

Synthetic aperture radar (SAR) systems are susceptible to radio frequency interference (RFI). The existence of RFI will cause serious degradation of SAR image quality and a huge risk of target misjudgment, which makes the research on RFI suppression methods receive widespread attention. Since the location of the RFI source is one of the most vital information for achieving RFI spatial filtering, this paper presents a novel location method of multiple independent RFI sources based on direction-of-arrival (DOA) estimation and the non-convex optimization algorithm. It deploys an L-shaped multi-channel array on the SAR system to receive echo signals, and utilizes the two-dimensional estimating signal parameter via rotational invariance techniques (2D-ESPRIT) algorithm to estimate the positional relationship between the RFI source and the SAR system, ultimately combines the DOA estimation results of multiple azimuth time to calculate the geographic location of RFI sources through the particle swarm optimization (PSO) algorithm. Results on simulation experiments prove the effectiveness of the proposed method.

Highlights

In order to calculate the exact geographic location of multiple radio frequency interference (RFI) sources of synthetic aperture radar (SAR) with taking into account the two-dimensional DOA estimation requirements and the complexity of the system calculation, this paper presents a new method for the location of multiple independent RFI sources combining two-dimensional estimating signal parameter via rotational invariance techniques (2D-ESPRIT) and the particle swarm optimization (PSO)
On the basis of this system, the RFI transmitted from multiple different spatial locations and existing at the same time is simulated, and the contaminated echo signals received by the SAR under these conditions are obtained
The interference signal of all RFI sources, the real target echo signal, and the noise signal constitute the echo signal of the SAR system according to Equation (1)

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. As an active microwave remote sensing device, synthetic aperture radar (SAR) has achieved excellent performance in resource exploration, military reconnaissance, and other earth observation missions. The electromagnetic environment in which SAR works is becoming more complex, its working frequency bands are occupied by radio devices such as broadcasting and ground radar. For the SAR system, the signals emitted by these devices are generally called radio frequency interference (RFI) [1,2]. RFI usually causes bright lines and spots in SAR images, which dramatically degrades SAR image quality and masks targets of interest, severely weakens the performance of SAR [1,2,3,4,5]

Methods

Results

Discussion

Conclusion