Wall clutter mitigation using a modified subspace projection method for non-parallel measurement through-the-wall radar imaging

In this paper, a modified subspace projection method for non-parallel measurement through-the-wall radar imaging is proposed. The proposed modified subspace projection method includes equivalent time delay and normalization to remove wall clutter. Synthetic data are obtained using a finite-difference time-domain forward solver to verify the validity of the proposed method. The target-to-clutter ratio of the delayed-sum migration image after the proposed method was improved 21.6 dB compared to the conventional subspace projection method.

I. Introduction

The basic idea of the conventional subspace projection method is that the most significant terms of the spectrum of the data matrix are dominated by the wall clutter. Using singular value decomposition, responses from the wall can be mitigated by excluding some dominant singular vectors [2].