Adaptive 3D Imaging for Moving Targets Based on a SIMO InISAR Imaging System in 0.2 THz Band

Abstract

Terahertz (THz) imaging technology has received increased attention in recent years and has been widely applied, whereas the three-dimensional (3D) imaging for moving targets remains to be solved. In this paper, an adaptive 3D imaging scheme is proposed based on a single input and multi-output (SIMO) interferometric inverse synthetic aperture radar (InISAR) imaging system to achieve 3D images of moving targets in THz band. With a specially designed SIMO antenna array, the angular information of the targets can be determined using the phase response difference in different receiving channels, which then enables accurate tracking by adaptively adjusting the antenna beam direction. On the basis of stable tracking, the high-resolution imaging can be achieved. A combined motion compensation method is proposed to produce well-focused and coherent inverse synthetic aperture radar (ISAR) images from different channels, based on which the interferometric imaging is performed, thus forming the 3D imaging results. Lastly, proof-of-principle experiments were performed with a 0.2 THz SIMO imaging system, verifying the effectiveness of the proposed scheme. Non-cooperative moving targets were accurately tracked and the 3D images obtained clearly identify the targets. Moreover, the dynamic imaging results of the moving targets were achieved. The promising results demonstrate the superiority of the proposed scheme over the existing THz imaging systems in realizing 3D imaging for moving targets. The proposed scheme shows great potential in detecting and monitoring moving targets with non-cooperative movement, including unmanned military vehicles and space debris.

Curved Synthetic Aperture Radar for Near-Field Terahertz Imaging

“…The capabilities of radar based 3D imaging and sensing has also been recently investigated for various applications including topographic mapping [48], deep learning based approach for moving object localization [49], indoor human vital signs and gesture/activity/posture localization, monitoring and classification [50], [51] and other applications in the THz, radio and microwave frequencies [52]- [60]. The capability of SAR technology to achieve 3D imaging and the exploration of efficient reconstruction algorithms in THz and Microwave frequency bands have been reported in various studies including [40], [61]- [65].…”

Broadband Photodetectors and Imagers in Stretchable Electronics Packaging

“…[45][46][47][48] The light-like directness of THz provides high spatial resolution and radio wave-like trans-parency for soft materials. [49][50][51] These characteristics allow for fluoroscopic imaging, including X-ray imaging, to be conducted at low energy levels with minimal exposure, and micrometersized metal detection is possible. In addition, similar to IR spectroscopy, a vibrational spectrum (fingerprint spectrum) derived from a molecular structure can be quickly identified through THz spectroscopy because intra-and intermolecular vibrations exist in the THz frequency region.…”

Fast and High-Quality 3-D Terahertz Super-Resolution Imaging Using Lightweight SR-CNN

“…In recent years, this has been further developed and has boosted radar imaging techniques for both microwave and terahertz (THz) radar [13][14][15][16][17][18]. Compared with 3-D imaging using microwave radars, THz radars take advantages of a higher carrier frequency and wider absolute bandwidth, which can form higher range resolution and reach better azimuth resolution with smaller rotating angel conspicuously [19][20][21][22][23][24][25]. THz radar imaging will no longer be limited to some isolated points, and attain the high-resolution image with the obvious target outline.…”