High-resolution through-wall ghost imaging algorithm using chaotic modulated signal

Abstract

In this paper, a novel high-resolution through-wall ghost imaging (TWGI) algorithm is proposed for detecting targets hidden behind walls. By using chaotic modulated signals, ghost imaging (GI) derived from optical image reconstruction applications is introduced and applied in through-wall imaging (TWI) scenarios to achieve high-resolution imaging capability. The scattering coefficients of the target imaging plane are treated as levels of brightness in the proposed algorithm, whose spatial distribution can be retrieved by processing the estimated electromagnetic (EM) field at the target imaging plane with the reflected signal captured by a single receiving antenna. Simulation results are presented to show the effectiveness and high quality of reconstruction results by using the proposed TWGI algorithm.

Microwave Surveillance Based on Ghost Imaging and Distributed Antennas

“…Performing GI using microwave signals has been demonstrated to be suitable for long-range detections [13] [14] and through-wall imaging applications [12]. In this section, based on these previous research, we further deduce the feasibility of applying GI into microwave surveillance scheme using distributed antennas.…”

“…where δ is the scattering coefficient of the single point target, and τ i is the propagation delay [18]. Chaos waveforms share the same statistically-independent feature with random noise, but they are easier to be generated and controlled [12]. Therefore, in our case the S i (t) in equation (5) represents the chaotic modulated signal transmitted by the ith transmitting antenna, which can be generated using the following cubic mapping sequence,…”

“…In this letter, in order to achieve high-quality performance with low system complexity, we introduce GI mechanism into microwave surveillance scenarios. Based on our preliminary work [12], GI's characteristics in imaging resolution and sampling requirement are further analyzed, then a GI and distributed antennas based microwave surveillance method are proposed. Meanwhile, chaotic modulated signals are employed to generate spatially incoherent electromagnetic (EM) fields for illumination, which are later processed with uniquely sampled reflected signals captured by a single receiving antenna for image reconstruction.…”