3-D Near-Field Passive Radar Imaging Using Multiple Illumination Sources

TL;DR

This paper introduces a multi-illumination approach for near-field passive radar imaging that combines results from multiple transmitters to improve image quality and reduce artifacts, validated through simulations and measurements.

Contribution

The paper proposes a novel multi-illumination method using multiple transmitters and coherent summation to enhance near-field passive radar imaging performance.

Findings

Improved imaging of complex objects with concave structures.

Reduction of artifacts and unilluminated regions.

Validation through simulations and real measurements.

Abstract

Near-field (NF) passive radar imaging depends on the illumination of the imaging scene by a non-cooperative transmitter (Tx). It is demonstrated that combining imaging results obtained with Tx antennas at different positions can enhance the performance of passive radar imaging. On the one hand, multiple Tx antennas provide diverse illumination perspectives, reducing the likelihood of unilluminated regions on the targets of interest (TOIs). On the other hand, the coherent summation of imaging results obtained for different illuminations helps to suppress potential artifacts. This approach is in particular advantageous for imaging complex objects with concave structures such as dihedral arrangements, where the ghosts due to multiple reflections are highly configuration-dependent. For each illuminating configuration, a single-frequency inverse source solver is utilized to reconstruct the equivalent sources of the TOIs and the resulting single-frequency images are then superimposed coherently with corresponding phase and magnitude correction methods. The obtained multi-frequency images are finally coherently combined to enhance the imaging quality. Both simulation and measurement results are presented to validate the effectiveness of the approach.