OAM-based radar imaging of electrically large realistic targets using scattered echoes

Area of Science:

• Electromagnetic wave propagation
• Radar systems engineering
• Computational electromagnetics

Background:

• Current orbital angular momentum (OAM) imaging research primarily addresses ideal point scatterers.
• The imaging characteristics of electrically large, realistic targets using OAM radar are not sufficiently explored.

Purpose of the Study:

• To investigate OAM-based radar imaging for electrically large realistic targets.
• To bridge the gap between point-scatterer OAM imaging models and realistic-target imaging using scattered echoes.

Main Methods:

• Computed scattered echoes of realistic targets using the angular spectrum decomposition method (ASDM) and physical optics (PO) method.
• Employed one-dimensional angular-azimuth imaging, two-dimensional range-angular-azimuth and range-cross-range imaging, and three-dimensional image reconstruction.
• Utilized the polar format algorithm (PFA) with four-nearest-neighbor interpolation and analyzed the effects of Bessel-function modulation and topological charge.

Main Results:

• Demonstrated the potential of vortex waves for target reconstruction of realistic targets.
• Examined the influence of signal-to-noise ratio (SNR), viewing angles, and target-position mismatch on imaging quality.
• Analyzed the imaging behavior of a blunt cone target under various conditions.

Conclusions:

• OAM-based radar imaging shows significant promise for realistic target reconstruction.
• This simulation-based study provides theoretical support for OAM-based radar detection systems.
• Identified current limitations and areas for future research in OAM radar imaging.