Three-Dimensional Imaging of Terahertz Circular SAR with Sparse Linear Array

Area of Science:

• Electromagnetics and Remote Sensing
• Applied Physics
• Signal Processing

Background:

• Terahertz (THz) synthetic aperture radar (SAR) offers non-contact and harmless security screening capabilities for public areas.
• Achieving high-resolution, all-aspect 3D imaging with THz SAR is challenging due to hardware constraints related to short wavelengths and grating lobes.

Purpose of the Study:

• To develop a 3D imaging algorithm for THz SAR that overcomes the grating lobe problem caused by short wavelengths.
• To enable high-resolution, all-aspect 3D security imaging in public spaces using THz SAR technology.

Main Methods:

• A sparse linear array model based on the equivalent phase center principle was established to address hardware limitations.
• A 3D imaging algorithm was derived, incorporating a phase-preserving algorithm for 2D ground plane imaging and sparse recovery for height-direction scattering coefficient reconstruction.

Main Results:

• Numerical simulations and experimental data validated the effectiveness of the proposed 3D imaging algorithm.
• The study demonstrated the feasibility of applying THz radar for advanced security detection systems.

Conclusions:

• The developed sparse linear array model and 3D imaging algorithm successfully overcome the grating lobe issue in THz SAR.
• THz SAR imaging presents a viable and effective technology for enhanced security screening in public environments.