This paper presents a new image formation method for multi-polarization through-the-wall radar imaging. The proposed method combines wall clutter mitigation and scene reconstruction in a unified framework using multitask Bayesian compressed sensing. First, the radar signals are jointly recovered using Bayesian compressed sensing in the wavelet domain. Then, a subspace projection method is employed to mitigate the front wall reflections. This is followed by principal component analysis, which is used to compress the remaining wavelet coefficients and remove noise. A linear model is developed which relates the compressed wavelet coefficients directly to the image of the scene. For scene reconstruction, multitask Bayesian compressed sensing is further applied to simultaneously form the images associated with all polarimetric channels. Experimental results based on real radar data demonstrate that the proposed method improves image quality by enhancing target reflections and attenuating background clutter. Abstract-This paper presents a new image formation method for multi-polarization through-the-wall radar imaging. The proposed method combines wall clutter mitigation and scene reconstruction in a unified framework using multitask Bayesian compressed sensing. First, the radar signals are jointly recovered using Bayesian compressed sensing in the wavelet domain. Then, a subspace projection method is employed to mitigate the front wall reflections. This is followed by principal component analysis, which is used to compress the remaining wavelet coefficients and remove noise. A linear model is developed which relates the compressed wavelet coefficients directly to the image of the scene. For scene reconstruction, multitask Bayesian compressed sensing is further applied to simultaneously form the images associated with all polarimetric channels. Experimental results based on real radar data demonstrate that the proposed method improves image quality by enhancing target reflections and attenuating background clutter.
I. INTRODUCTIONThrough-the-wall radar imaging (TWRI) is emerging as a viable sensing technology supporting a range of civilian and military applications, such as search-and-rescue, law enforcement, and urban surveillance and reconnaissance. It can be used for various purposes, including determining the building layout, and locating and identifying stationary objects behind walls. In the past years, numerous studies have been conducted in modeling and imaging stationary and moving targets behind walls and inside enclosed building structures [1]- [4]. However, there is still a need for producing high quality images that can effectively discriminate the targets of interest from clutter without increasing the data acquisition time.Several TWRI studies have focused on the use of polarization of the electromagnetic (EM) waves for detecting targets or enhancing the discrimination of targets [5]-[11]. In [5], a method for through-the-wall detection of certain types of weapons was developed by analyzing the...