Advances and prospects in SAR microwave vision three-dimensional imaging

Synthetic Aperture Radar three-dimensional(3D)imaging enables the acquisition of more comprehensive information,making it a recent hotspot in radar imaging.Traditional 3D imaging methods have evolved from 2D and interferometric imaging,combining elevation aperture extension with signal processing techniques.Limitations such as long acquisition or complex system from its imaging mechanism restrict its application.In recent years,rapid development of artificial intelligence has led to a swift advancement in radar,injecting new vitality into SAR 3D imaging.SAR microwave vision 3D imaging theory,which is built upon advanced technologies,has emerged as a new interdisciplinary field for radar imaging.This paper reviews SAR 3D imaging’s history and present situation,and introduces SAR microwave vision.We establish a theoretical framework covering representation models,computational models,processing paradigms and evaluation systems.Additionally,our research progress in this area is discussed,along with future prospects for SAR microwave vision 3D imaging.

Photonics-enabled distributed MIMO radar for high-resolution 3D imaging

Three-dimensional(3D)imaging radar is an advanced sensor applied in space surveillance and target recognition for supplying 3D geometric features and supporting visualization.However,high 3D resolution requires both broadband operation and a large 2D aperture,which are difficult and complex for conventional radars.This paper presents a photonics-enabled distributed multiple-input and multiple-output(MIMO)radar with a centralized architecture.By use of photonic multi-dimensional multiplexing,multi-channel signal generation and reception are implemented on a shared reference signal in a central office,enabling a highly coherent network with a simple structure.Additionally,a sparse array and a synthetic aperture are combined to efficiently reduce the required transceivers,further weakening the dilemma between system complexity and angular resolution.A 4×4 MIMO radar is established and evaluated in field tests.A high-resolution 3D image of a non-cooperative aircraft is obtained,in which rich details are displayed.From a comparison with electronics-based radar,significant resolution improvement is observed.The results verify the superior imaging capability and practicability of the proposed radar and its great potential to outperform conventional technologies in target classification and recognition applications.