Imaging extended reflectors in a terminating waveguide

TL;DR

This paper presents a method for imaging extended reflectors in terminating waveguides by back-propagating the array response matrix, with resolution depending on frequency and improved SNR with bandwidth, tested on complex geometries.

Contribution

It introduces a projection-based imaging technique suitable for various array sizes and provides a detailed resolution and robustness analysis in complex waveguide environments.

Findings

Resolution is determined by the central frequency.

Signal-to-noise ratio improves with increased bandwidth.

Method is robust with complex geometries.

Abstract

We consider the problem of imaging extended reflectors in terminating waveguides. We form the image by back-propagating the array response matrix projected on the waveguide's non-evanescent modes. The projection is adequately defined for any array aperture size covering fully or partially the waveguide's vertical cross-section. We perform a resolution analysis of the imaging method and show that the resolution is determined by the central frequency while the image's signal-to-noise ratio improves as the bandwidth increases. The robustness of the imaging method is assessed with fully non-linear scattering data in terminating waveguides with complex geometries.